Gardening

Coleus: A Victorian Dream

By Abigayle Ward, UConn Dept. of Plant Science & LA Graduate Student

Red coleus in the middle of a flower garden
A bed of red coleus surrounded by magenta celosias, and baby pink and purple petunias, complete with a walking path dividing the bed in two. This circular bed is located at the end of Mansfield Road within the University of Connecticut Storrs campus.

Seen anywhere from great-grandma’s ornamental garden to your neighbor’s hanging basket, coleus are the colorful, velvet-textured leafy cousins of oregano and deadnettle. Native to tropical regions of Africa, Asia, and Oceania, it is thought that Dutch botanists introduced the fascinating foliage to Victorian England in the mid 1800s. Coleus were readily welcomed into homes as parlor plants and into ornamental gardens. They were especially coveted in so-called “carpet bedding” gardens, where bedding plants of equal height are used to create colorful designs such that they appear like “carpets” when viewed from above. Other than coleus, the Victorians enjoyed using colorful flowers such as petunias, asters, and zinnias as carpet bedding. Carpet bedding is still popular today; we have at least one such garden featuring coleus and petunias on display at the University of Connecticut Storrs campus. To design a carpet bedding garden, try combining simple shapes and lines to make symmetric, harmonious patterns. Use green vegetation, such as sedums, or even a green cultivar of coleus, to contrast with the bright colors of flowers and the mulch or soil below.

For those of us lacking yard space comparable to an English country house, a large carpet bed garden might be impractical. Instead, coleus can be planted alongside other flowers for a splash of color in a flower bed against a house or fence. Coleus are the perfect complement to the colorful clapboard siding characteristic of houses in New England – draw attention to the colors of both by putting reds with greens and yellows with purples. If coleus are planted directly into the ground, slugs are one major pest to look out for. In particularly wet summers, such as those in recent years, slug populations can devour entire coleus plants.

To avoid slugs, container gardens may be a wise option. Sitting above the ground and out of field soil, slugs will have more difficulty reaching the tasty, tender leaves. For those with outdoor space around their apartments, container gardens are also generally a renter-friendly option. Coleus grow well in window boxes and other small containers, and they can help add a warm, friendly atmosphere to the entrance of any home. Most cultivars of coleus available on the market today are tolerant of both shaded and sunny conditions, and thus are well-suited to either covered or open porches. In containers, the main pests to look for are thrips, mealybugs, and aphids. These three pests can cause discoloration in leaves, such as silvery/gold, yellow, or black spots. Outside where predators of these pests thrive, infestations should not progress to the point of killing entire plants, but affected foliage may be unsightly. While systemic insecticides may help keep these types of pests off coleus, they also can kill bees. Avoid applying systemic insecticides to coleus outdoors whenever possible. Try moderately forceful sprays with water instead, insecticidal soap or other least toxic controls.

The Victorians also kept coleus as houseplants, and so can you. In plant hardiness zones 6a-7b in Connecticut, coleus are very tender annuals. They will grow prolifically when temperatures are above 60°F, and will experience cold injury if temperatures fall below 50°F. When temperatures plunge below 40-50°F and overnight frost becomes a possibility, leaves will start to blacken and die. At the end of the growing season before the first frost, consider planting stem cuttings in pots and bringing them indoors for colorful, year-round foliage. Coleus as houseplants will do best in north-facing or east-facing windows. Avoid placing them in windows where they experience too much direct sunlight for too long during the day. If windows are unavailable, coleus also grow decently under grow lights.

No matter where they are grown, the main attraction of coleus is its brilliant foliage. Plants grown in containers may benefit from occasional nitrogen additions to keep them growing all season long. Like others in the mint family, coleus grow flower spikes when stressed or when the plant is near the end of its life cycle. While the flowers on the spikes are not very attractive from an aesthetic standpoint, bees, hummingbirds, and other pollinators flock to them. While the spikes can be pruned off if they appear too early in the growing season to encourage further vegetative growth, consider leaving the late-season spikes on, so that bees can collect nectar to sustain their hives over the winter.

While the selection of coleus cultivars were limited in Victorian England, decades of horticultural breeding efforts have given us access to over 1,000 varieties today, including sun-tolerant cultivars, with endless colors, leaf shapes, sizes, and growth habits. Consider adding this versatile Victorian dream to your home garden for splashes of colorful summer foliage.

If you have questions on coleus or on other gardening topics, feel free to contact us, toll-free, at the UConn Home & Garden Education Center at (877) 486-6271, visit our website at www.homegarden.cahnr.uconn.edu or contact your local Cooperative Extension center.

Great Hostabilities

By Dawn Pettinelli, UConn Home & Garden Education Center

Hostas in a garden
Image by dmp2024

So versatile and ubiquitous are hostas that I have yet to visit a garden that doesn’t have at least one whether left by a previous gardener or selected by the present one. Hostas certainly are workhorses of the garden renowned for their shade tolerance, hardiness and longevity. Plus, few plants have such large variations in size, leaf color and texture. According to the American Hosta Society, there are more than 3000 varieties of hostas covering 45 species including stalwarts of our gardens such as Hosta sieboldiana, H. elegans and H. montana. Now the hostas you purchase are likely complex crosses of multiple species.

Hostas are native to Asia and came to the United States through Europe during the 1800s. Many of us older gardeners referred to them as plantain lilies because their broad leaves resemble a common weed (or herb depending on one’s perspective), plantain. The young leaves are reputedly edible. In fact, the Japanese are said to serve them raw, boiled or fried in tempura. Their palatability probably explains why gardeners around here half-jokingly refer to them as ‘deer candy’.

Hostas are divided by size into 5 groups. Minis are less than 6 inches tall, small range from 7 to 10 inches, medium from 11 to 18, large from 19 to 28, and giants are greater than 28 inches. ‘Gentle Giant’ and ‘Empress Wu’ are close to 4 feet tall with a spread of over 5 feet, if you’re looking for a plant to make a voluminous impression. Keep in mind a plant’s full size when incorporating them into your planting beds.

A notable feature of many hosta cultivars is leaf variegation. On marginally variegated plants the edges of the leaves are light in color, maybe cream or yellow. Medio variegated types have light colored centers with darker edges. There are also 5 groupings for color: green, blue and gold, plus the 2 types of variegation. The gold and variegated cultivars do best in part sun to dappled shade. Placed in a heavily shaded area, they can lose some of their color as only the green parts of the leaves photosynthesize.

Hosta leaves up close with raindrops
Image by dmp2024

Leaf shapes range from thin and smooth to ridged and heart shaped. Sizes range from 2 inches on ‘Mouse Ears’ to over a foot and a half on giant hostas.

While grown mainly for their attractive foliage, hostas do bloom once a year. Most have delicate-looking, tubular flowers in various shades of purple that are attractive to hummingbirds and bees. Fragrant white ‘Royal Standard’ grace part of a patio in my white garden. Their heady scent is especially pronounced on warm summer evenings. ‘Royal Wedding’ is another fragrant, white-flowering variety. Cut down the flower stalks once flowering is finished.

Growing hostas is a breeze. These tough, dependable plants put on their best show when not located in full sun as the large leaves can scorch during periods of hot, sunny weather. That being said, there are some cultivars like ‘Guacamole’ and ‘Paradigm’ which can tolerate full sun with adequate moisture.

An ideal location would be a semi- to fully shaded site in a soil with a pH in the mid 6s and moderate fertility. Hostas are often planted under trees as once established they can tolerate dry shade to some extent. Remember that a tree’s roots will be competing with the hostas and your plants would benefit from extra water and fertilizer.

The two major pests of hostas are slugs and deer. Ragged holes and tears on leaves are a sign of slugs. These soft-bodied creatures feed at night or on cloudy days but slime trails on the leaves or ground may be visible in the morning. Controls include hand-picking, beer traps, diatomaceous earth and slug baits.

Deer can make short work of a bed of hostas. Three strategies are to use repellents, fence them out or plant your hostas amid less appetizing plants. Some have reported less deer damage to blue leaved hostas, maybe because they have a waxy coating. If you’re growing hostas in deer country, you’ll have to figure out what works best for you.

At the end of the season, frost will flatten the leaves of your hostas. Cut them back and remove the foliage from your garden to give both slugs and diseases less places to overwinter. Plants typically need division every few years if they are outgrowing their allotted spaces. Dig up and divide in the spring when the new stems start to poke through the soil but before the leaves unfurl.

If you have questions about growing hostas or any other gardening questions, feel free to contact us, toll-free, at the UConn Home & Garden Education Center at (877) 486-6271, visit our website at www.homegarden.cahnr.uconn.edu

Firefly Petunias Light Up the Night

By Dr. Matthew Lisy, UConn Adjunct Faculty

A pot of white flowered firefly petunias
Firefly Petunias by Day. (Photo by M. Lissy)

The world of genetics has really had a tremendous impact on our lives. There is a lot of talk about GMOs, or genetically modified organisms, in the news. Labels even alert us to the presence of these crops in our foods. I wanted to share a new plant called the Firefly Petunia. It was not fireflies, but mushrooms that gave this plant its ability to glow. This is known as bioluminescence in the world of biology.

Through feats of genetic engineering, a gene is taken from one organism and placed into another.  This is where people become worried. Humans, however, have been doing this for hundreds of years. The best looking or most productive organisms were bred together for the next generation.  This is called selective breeding, and it essentially concentrates beneficial versions of genes in the offspring.

Now what is determined to be the most beautiful is truly in the eye of the beholder. Some people, for example, selected for white flowers in a normally purple flowered species, Echinacea purpurea. Some have even taken things a step farther and crossed different species of plants to obtain new colors of flowers. In nature, separate species have evolved isolation mechanisms to maintain their identity. When our plant breeders force a cross of the species boundary, much of the time it was done with closely related species of plants within the same genus.  A great example of this is the crossing of Echinacea purpurea, the purple cone flower, with Echinacea paradoxa, the yellow cone flower. This was done to obtain hybrid offspring that have red or orange flowers. These were back crossed with the parent varieties, so they have the same growth habit and form, but with new colored flowers.

Firefly petunia flowers glowing green in the dark.
Firefly petunias by night. This is no trick, the plants actually glow (photo by M. Lisy)

This hybridizing never really ruffled many feathers though, as the plants were very closely related anyway. More modern GMOs, like our Firefly Petunias, are obtained not through “natural” pollination processes, but through genetic manipulation. Scientists literally take one or more genes from one species and place them in another. These species are not closely related, so it may become an ethical conundrum. Here, one may ask if we should take a gene from a mushroom and place it into a plant. A similar circumstance was seen over twenty years ago in the aquarium industry, where genes from corals and jellyfish were placed into tropical fish to make them fluorescent Glofish.

On the question of ethics, I cannot tell you what to think, or what is right or wrong. We each will need to answer that question for ourselves. It does remind me of a quote from Jurassic Park, where Dr. Ian Malcolm states “…your scientists were so preoccupied with whether or not they could that they didn’t stop to think if they should.” The real question is where do we go from here. For the fish, it was species after species of Glofish, and for me, the novelty started wearing off. After all, how many species will be made fluorescent before it just gets boring? Now for our plants, will we have roads lined with glowing trees to eliminate the need for streetlights? Will we have glowing houseplants that function like night lights? Ultimately, it will be up to you, the consumer.

For me, this is just cool science. We ship and plant petunias all over the world. Are these glowing petunias going to cause any harm? Probably not, as none of the other ones have. When I go outside at night to take the dog out and see the bioluminescent petunias, it puts a smile on my face. It reminds me of the fact that we, as humans, are capable of many things. I can’t help but ponder if this will inspire a sense of awe and wonderment in our children. Maybe some may even study genetics because of these petunias. What if one of them ends up finding a cure for a debilitating human disease, all because of a glowing plant? And while some may say that this daydream of mine is just science fiction, need I remind you that so were glowing plants a few years ago?

For your gardening questions, feel free to contact us, toll-free, at the UConn Home & Garden Education Center at (877) 486-6271, visit our website at www.ladybug.uconn.edu or contact your local Cooperative Extension center.

 

Keep your Perennials & Annuals Looking Fabulous All Season Long!

By: Heather Zidack, UConn Home & Garden Education Center

Geraniums and other flowers in a mixed container
Geraniums benefit from regular deadheading. They’re great for beginners because it is easy to tell the difference between new and spent flowers. Photo by H. Zidack

Hanging baskets, planter boxes and perennial gardens that are bursting with color are seldom planted in spring and left untouched until autumn. Deadheading, pruning, trimming and pinching are all techniques that gardeners can use to get that perfect look all season long. While it may be intimidating, this simple task can result in a huge visual impact with only a little effort. Through a series of pruning techniques, we manipulate our perennials and annuals to give us the most beauty we can get out of them in such a short season. It is important to recognize that cutting healthy flowers or shoots can help plants in the long term – no matter how much it may pain us as gardeners to do so.

Deadheading is a widespread practice where gardeners remove flowers that have gone by. One of the first things to become aware of is the difference between a bud and a spent bloom on the plant you are working on. Many gardeners will snip petunia buds, mistaking them for spent flowers. It is important to be vigilant with these cuts. Remember that your plant's goal is to reproduce, and they use flowers to do so. By removing the flowers, you are stopping the plant from producing seed and encouraging it to restart the cycle – meaning more flowers for you!

Some gardeners will select “self-cleaning” varieties of annuals that will shed their flowers without the need to deadhead all summer long. In general, these may not produce seed; therefore can easily restart the process themselves.

The whole practice of deadheading, pinching and trimming herbaceous plants can be boiled down to redirecting the plants energy into different purposes. Where deadheading helps to clean spent flowers, pinching will remove new buds before they bloom. If you want to encourage beautiful single stem cut flowers, for example, you may decide to pinch lateral (side) flower buds to force the plant to put all its energy into a single bloom at the top. Alternatively, pinching the terminal (top) bud will give you many smaller flowers on one stem, creating a fuller appearance.

This same principle applies to pinching shoots of herbaceous plants to make them fill out more. Cutting further down a stem will again remove that terminal bud and cause the plant to focus its energy on new shoots that come from nodes further down the stem. Think of how full your basil plants flush out when you harvest fresh herbs.

Torenia hanging basket
Torenia is considered a self-cleaning annual that is great for shade and is loved by hummingbirds! Photo by H. Zidack

Often, gardeners will notice that in mid to late summer their hanging baskets will start to look “tired.” They may notice prolific flowering on the ends that hang down, but often see that the center of the basket is not as full or may even be dying out. The first thing to check for is to make sure that you are watering them regularly. Because hanging baskets are suspended in the air and uninsulated, they will dry out faster. When you are trimming herbaceous plants for growth you can take one third of the plant volume away at a time, safely. Think about it as playing hair stylist! Cut back one third of the longest growth at the ends, and watch new growth come from the roots. It may also help your hanging baskets to remove any branches that have been shaded or dried out in the interest of “lightening” the growth that is hanging down.  Again, you may lose flowers for a week or two – but the result down the road will be beautiful!

For perennial gardens, June is a wonderful time to do some pruning as well. Cutting back early flowering perennials can encourage a second flush of flowering in some species. This works exceptionally well for plants like Salvia, Nepeta, and Lavender. Deadheading throughout the season will help plants like roses and Echinacea continuously flower. And pinching can help perennial mums form their shape for the fall.

Summer is a stressful time for plants! Disease, pests, and extreme weather can all contribute to a stressful environment. Our New England summers can promote these pressures with high heat and humidity levels. During these times, pay careful attention to your watering habits and adjust, as necessary. In times of drought or excessive heat, plants will use water faster for hydration and cooling, just like we do. Being aware of this can help you know when to check for water and help you be more diligent with your watering practices. Using a balanced, water-soluble fertilizer can also promote plant health and reduce stress in perennials and annuals. This is why it is great to fertilize after pruning and deadheading. If you need more information on trimming, watering, fertilizing, or any other gardening questions, feel free to contact us, toll-free, at the UConn Home & Garden Education Center at (877) 486-6271, visit our website at www.homegarden.cahnr.uconn.edu

Luscious Lemony Herbs

By Dawn Pettinelli, UConn Home & Garden Education Center

With summer almost around the corner, many of us are setting in vegetables and herbs in hopes of preparing delectable culinary delights as these plants mature. Aromatic herbs bring amazing flavors and zing to all sorts of savory and sweet concoctions. A citrusy taste complements many dishes and some may not be aware of the wealth of lemon-flavored herbs that are widely available and also easy to grow.

Lemon balm plants up close.
Lemon Balm in the garden. Photo by dmp2024

Long-lived lemon balm has been a staple in my herb garden for years. The attractive heart-shaped, scalloped leaves have a delicate scent when rubbed. Lemon balm is a hardy perennial native to Europe and has long been grown for its culinary and medicinal purposes. Fresh or dried leaves can be made into a calming tea that reputedly reduces anxiety. They can also be used in savory chicken dishes, to make pesto and even in baked goods. The lemon balm I grow is the species and it produces flowers that, like many members of the mint family, are loved by bees. A dilemma ensues as to whether to leave the blossoms for the pollinators and deal with the copious seedlings that pop up the following year, or cut the plant back to encourage more leaf production. Also, once lemon balm flowers, the leaves take on an unpleasant ‘soapy’ taste. Cultivars such as ‘Compacta’ are sterile, so no seeds are produced.

As long as it is grown in a well-drained soil, lemon thyme is another long-lived herb. Growing just 4 to 6 inches tall, it’s an attractive plant in the herb garden, as an edging plant or even as a front border plant in perennial gardens. There are green, golden, and variegated leaved cultivars. Sprigs of lemon thyme can be dried but I like to use them fresh in chicken or rice dishes. The pinkish flowers usually open in July and are a big pollinator draw. Like many herbs, the best flavor is obtained collected before flowering. Plants respond well to regular trimmings.

Lemon basil is an annual in our climate but easily grown from seed. Like all basils, it does best in a sunny, fertile site with adequate moisture. Plants also do great in containers. Leaves have a fresh lemony scent and taste with some hints of mint and spices. If growing from seed, one might want to try ‘Sweet Dani’, which was a 1998 All America Selection winner. Named cultivars such as ‘Mrs. Burns’ lemon basil usually have larger leaves than the seed grown types. Pinch out flower stalks as they form for better flavor or for a longer and more abundant harvest, cut off the top third of your plants about once a month. This encourages greater branching and leaf production. Lemon basil rice is my favorite way to use fresh leaves.

Lemon grass in a garden bed.
Lemon grass in the garden. Photo by dmp2024

A tender perennial, lemon verbena, is mostly grown as a container plant and overwintered indoors. Plants have an exceptionally strong lemon scent and if happy, grow quite vigorously. They can easily get 3 or 4 feet tall and will grow into a small tree in warmer climates. Lemon verbena is native to South America, so it enjoys full sun and hot weather. Leaves can be used in potpourris, teas, and sweets.

Another tender perennial best grown in a pot is the lemon scented geranium. There are several named cultivars with some, like ‘Mabel Gray’ and ‘Rober’s Lemon Rose’, having a stronger scent. Either buy plants or start from a friend’s cutting. The lovely scented wavy leaves can be placed in the bottom of a cake or loaf pan and then filled with batter and baked, imparting a lovely pattern and slight lemony flavor. They can be used fresh or dried for a variety of culinary uses and are also good in potpourris.

Those enjoying Asian cooking are likely already familiar with the rich flavor of lemon grass. While it is native to India and only hardy to zone 10 to 12, it is a pretty vigorous grower that would do well in either a garden bed or container. Reportedly plants may reach 2 to 3 feet in height by midsummer if kept well-watered. The leaves as well as the bulbous base of

the stem are used in recipes. A few stalks can be removed as needed for cooking. Cut back potted plants to 6 inches before overwintering in a sunny window indoors.

For more information about growing lemon scented herbs or on other gardening topics, feel free to contact us, toll-free, at the UConn Home & Garden Education Center at (877) 486-6271, visit our website at www.homegarden.cahnr.uconn.edu or contact your local Cooperative Extension Center.

DIY – Grow Flowers for Cutting

By Dawn Pettinelli, UConn Home & Garden Education Center

Cut flower arrangment
Fresh cut flowers - Photo by dmp2024

Do you just love fresh flower arrangements for the table or even that single bloom in a vase by your bedside? Wouldn’t it feel great to just stroll out your back door, clip some blossoms, bring them inside and enjoy their beauty? There’s no reason that you can’t. Even a small yard or garden space can yield blossoms for cutting.

While many of us have flowering perennials and even woody plants that make for great arrangements, perhaps a dedicated cut flower planting would provide many more stems for cutting and not create any empty spaces in our garden designs. When planning your cut flower garden, first decide where it should go. The majority of blooming plants need at least 6 to 8 hours of sun each day, a well-drained, fertile soil and adequate water during dry spells. As with all garden plants, a soil test is a great way to find out what is needed to add to soils before planting but without a soil test, follow the directions on fertilizer packages.

There’s still time to prepare new beds for cut flower plantings but another alternative would be to turn over part of the vegetable garden to cut flower production. Probably your vegetable garden already has great soil and is located in a sunny area.

The hardest part of designing a cut flower garden is selecting what plants to grow. There are so many beautiful and exciting flowers to choose from. A good suggestion is to grow easy flowers at first and then progress on to more demanding ones. Another important factor to consider is which flowers need to be purchased as transplants (or started inside earlier under lights) and which can be easily grown by sowing seeds directly in the garden. While there are a number of flowering plants that can be started by direct seeding, you’ll get faster blooms if you purchase or grow your own transplants.

Zinnias planted in a row
Zinnias - Photo by dmp2024

Some that I typically grow each year from seed are zinnias, the tall African marigolds, cosmos, bachelor buttons, calendulas, nasturtiums, and some sunflowers. Cool weather calendulas and bachelor buttons can be sown now but wait until later in the month to plant the rest. A number of cutting annuals will self-seed if blossoms are allowed to mature and the beds are not heavily mulched. Some that spring up for me include ageratums, verbena, ammi, nigella, and wheat celosia. If you have some known self-seeders, wait a bit longer to prepare or till beds to see what sprouts.

Those best purchased as transplants include rudbeckia, snapdragons, cleome, stock, strawflowers, globe amaranth, tithonia, asters and amaranth. Some might have tiny seeds or be slower to germinate or just need a longer time until they produce flowers so starting with transplants may be a good option.

Two annual bulbs that are great for cutting are gladioli and dahlias. A few glad corms can be planted every other week until about mid-June to provide a summer full of spiky, colorful blooms. Dahlia tubers planted mid-May generally start producing blooms by late July but continue until a heavy frost.

There really are quite a few potential cut flower candidates to choose from. Feel free to select whatever colors and flower forms appeal to you most. From a designer’s viewpoint, consider what colors would be most compatible with where you want to place arrangements indoors. Also, whether making more formal arrangements or informal bouquets, flower shape plays a prominent role. Often the most attractive arrangements are filled with an assortment of shapes featuring a focal flower, spiky exclamation points, mounded shapes to hold the arrangement together, greenery for filling spaces and delicate airy springs to lighten the mood. I find mints, artemisia, and ferns make good fillers while grasses, kalimeris, boltonia, and white wood asters provide an airy touch.

The majority of annual flowers do fine at about a 9 by 9 inch spacing so you can pack them in pretty close. Do note that for copious blooms, a fertile soil and adequate water are essential. Maintenance also includes dead-heading, or removal of spent flowers to encourage the production of more blooms. Keep an eye out for plant pests as well.

Even beginning gardeners can set aside some space to grow beautiful flowers for enjoyment indoors. Try out a few this year, make notes on their performance and change up the plant rooster as they gain your approval or not.

For cultural information on growing various species of cut flowers or on other gardening topics, feel free to contact us, toll-free, at the UConn Home & Garden Education Center at (877) 486-6271, visit our website at www.homegarden.cahnr.uconn.edu or contact your local Cooperative Extension center.

 

 

 

Gardening for Climate Change with Connecticut Public

Connecticut Public: Where We Live - 4/26/2024
This year, we're gardening with climate change in mind

Dawn Pettinelli from the UConn Soil Nutrient Analysis Lab & Home and Garden Education Center joins Catherine Shen & Charlie Nardozzi on Connecticut Public to discuss ecological gardening and strategies for gardening for the environment.

Start Now For a Rosy Summer

By Dawn Pettinelli, UConn Home & Garden Education Center

A rose shrub in full bloom
Proper care of your roses will give you lots of blooms. Photo by dmp2024

The warmer days of spring will soon be upon us and it is time to think about spring rose care. Any winter protection such as mounded soil, mulch, leaves or rose cones that were placed around grafted bushes should be removed. Release any stems that were tied for winter protection. Fertilize your plants when new growth sprouts with a complete fertilizer such as 5-10-10 or and natural organic equivalent at the rate recommended by a soil test or follow the manufacturer’s instructions on the package. Generally, the fertilizer is sprinkled around the base of the plant and gently worked into the top of the soil.

Repeat blooming roses are heavy feeders and ideally should be fertilized monthly through July. Stop fertilizing at this time as later fertilizations may result in tender new growth late in the season that may not have time to harden off properly. Roses that bloom only once in June are usually only fertilized once in the spring. These include many ramblers and climbers, species roses and antique varieties. Rose books often recommend a dose of Epsom salts for each rose to supply magnesium. If you use a dolomitic limestone to modify the soil pH, however, the plants will most likely have enough magnesium available to them and additional magnesium will not improve growth or branching. Note that according to the American Rose Society, roses prefer slightly acidic soil so strive for a pH between 6.0 and 6.5..

climbing hybrid tea rose ‘Climbing Tangerine.’
This climbing hybrid tea rose is called ‘Climbing Tangerine.’ Photo by dmp2024

Most types of roses benefit from a spring pruning with the exception of climbing roses which are generally pruned immediately following flowering. Roses are pruned to improve their appearance, to remove diseased or dead wood and to increase the quantity and quality of flowers.

Polyanthas, floribundas and shrub roses do not require much pruning. Any canes that are damaged or broken should be removed as well as canes that are rubbing together. If just the tip of the stem is winter killed, cut back to sound wood just above a healthy bud. Rose bushes that are really overgrown can have about one-third of their canes removed from the base.

Hybrid teas and grandifloras usually require more severe pruning. After eliminating all dead and damaged wood, cut back to 18 to 24 inches. Make your pruning cuts at a slant slightly above a bud, preferably one oriented away from the center of the plant.

If your roses are grafted, it is also important to remove any suckers arising from the rootstock.

Spring is a great time to add a few more roses to your garden. Roses are soil either bare-root or as container plants. Those sold in containers can be planted either in partial leaf or full leaf. Mail ordered bare-root stock, however, should be planted when it is still dormant. It is best to plant bare-root roses as soon as you get them. If planting has to be delayed for a day or two, remoisten the packing material and store in a cool, shady location. When it is time to plant bare-root stock, unpack the plant and place the roots in warm water for an hour or two. Cut off any dead or injured parts and plant immediately after soaking.

Roses require a minimum of 6 hours of sun each day for maximum bloom. An area with good air circulation will cut down on disease problems. Soil type is not as important as drainage. Roses will not tolerate wet feet.

When planting grafted plants, set the bud union, which is the point where a rose cultivar is grafted to the root stock, about one inch below the soil level. Roses require about one inch of water per week. If at all possible do not get the leaves wet when watering as this promotes the spread of diseases such as black spot.

Roses benefit from the application of an organic mulch like shredded bark, pine needles or cocoa bean hulls. Mulches not only keep weeds down but help conserve moisture. If you have any questions on roses or other gardening topics, contact the UConn Home & Garden Education at (877) 486-6271 or www.homegarden.cahnr,uconn.edu or your local Cooperative Extension Center.

It’s Spring! Time to Feed the Plants!

By Dawn Pettinelli, UConn Home & Garden Education Center

Plants need nutrients to grow and develop just like we need vitamins and minerals. They get most of their nutrients dissolved in the water they take up with their roots. When we add fertilizer to the soil around our garden plants, we are adding vital plant nutrients.

Native Connecticut soils are typically low in pH and low in nutrients. Our native plants have adapted to our native soils but most of our garden plants are not from around here. Zinnias and tomatoes are from South America, bluegrass lawns and lilacs hail from Europe and rhododendrons from Asia. Our native soils may not supply the nutrients they need so it is up to us to do so.

Of course, the best way to know which nutrients and how much to add is with a soil test. April is a very busy month at the UConn Soil Nutrient Analysis Lab (www.soiltesting.cahnr.uconn.edu) but there is still time to get your soil tested before planting.

Without soil test recommendations, always follow the directions on the fertilizer package. Applying too much can injure your plants plus excessive nitrogen and phosphorus can wind up in our waterways. Before fertilizing, calculate out the square footage of your garden or lawn. You don’t need to measure exactly; you can measure a pace and then walk down the length and across the width of your gardens to get a rough estimate of area. For odd-shaped beds or lawns, break them down into more square, oval or rectangular areas and add them up.

All fertilizers come with 3 numbers on the package denoting the percent, on a dry weight basis, of nitrogen, phosphorus and potassium. Nitogen promotes green, leafy growth, phosphorus encourages fruits and roots, and potassium is for all round health and tolerance to stresses like drought, cold and disease. So, fertilizers with a higher nitrogen number would be most appropriate for turf grasses, trees and shrubs, while ones higher in phosphorus are generally used in vegetable and flower gardens.

Adding fertilizer to perennials with a watering can and a hand rake.
Fertilizer spread around a perennial. Photo by dmp2024

Whether you select a synthetic or natural organic fertilizer is a matter of personal choice. Both are beneficial to plants. For annual plantings, whether vegetable or flowers, it would be ideal to mix the fertilizer into the top 6 inches of soil. That’s where most of the roots will be so it makes sense that the nutrients they need are there too. Put down the fertilizer, as well as any limestone or other amendments shortly before planting. Long season annuals, like tomatoes, pumpkins and marigolds would appreciate a second application of fertilizer, referred to as side dressing, about 2 months after the first one.

As you are cleaning up your perennial beds and see the new shoots popping through the soil, add some fertilizer around plants and carefully scratch it in. Do the same for bulbs. It is harder to fertilize if the beds are heavily mulched. Not much fertilizer spread on top of mulch will make it to the plant roots. Rake or pull away the mulch, sprinkle some fertilizer directly to the soil around your plants and replace the mulch.

For trees and shrubs, fertilizer should be spread under the whole canopy as a healthy root system will grow at least as wide as the branches and perhaps even more so. Do your best to remove the mulch before fertilizing. Typically trees and shrubs are fertilized once a year in the spring. Once they have reached their mature size, often the fertilizer is cut down to half rate as woody plants can recycle many of the nutrients they need.

Lawns can be fertilized now but pay attention to the moisture level of the soil. With all the rain that we have been experiencing, the soil is pretty soggy in spots. Stay off wet soils as they will become compacted. Most lawns do well with just a spring and fall application of fertilizer. If the clippings are left down, they supply nutrients plus add organic matter to the soil. Be sure to set your spreader on the proper setting.

If you have questions about fertilizing or if you have any other gardening questions, contact the UConn Home & Garden Education at (877) 486-6271 or www.homegarden.cahnr,uconn.edu or your local Cooperative Extension Center.