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Remove Those Suckers!

By Dawn Pettinelli, UConn Home & Garden Education Center

About now the gardens should be planted, and it is time to turn our attention to the trees and shrubs on the property. New growth is almost fully expanded and pruning of spring flowering shrubs can commence. When out there with your pruners, keep an eye peeled for suckers and water sprouts, both on the plants you’re pruning and other woody plants in the yard.

Many trees and shrubs produce vigorous, upright stems that can reach several feet high over the growing season if left unchecked. Those arising from the root system are known as suckers while those growths arising from the crown portion of a tree or large shrub are referred to as water sprouts. At the very least, they are unattractive and take away from the architectural framework of a plant. More importantly they use water, nutrients and energy that could be put to better use if not taken from the rest of the plant. If not removed, they can crowd out the main plant resulting in reduced vigor.

Some woody plants naturally tend to produce suckers and sometimes these young vigorous shoots are needed to rejuvenate older plants as aging stems are removed. An example would be shrubs like red-twigged dogwoods or lilacs. Suckers arising from trees such as apples, crabapples, honey locust, lindens and others, however, should be removed.

In the case of grafted plants, like hybrid tea roses or apples, the desired variety is grafted on to a rootstock that might be more cold hardy, have dwarfing genes or other desired features. Occasionally the rootstock revolts, so to speak, and sends up its own shoots. In the case of roses, one might notice a stem with red flowers when the plant was purchased as a named cultivar with different colored flowers.

Suckers and water sprouts often occur because plants are in some way stressed or due to damage to their root system. Plants can be under stress for a number of reasons. Some common reasons would be insect or disease problems, drought, too high of a water table, compacted soil and/or difficult growing conditions.

Planting too deep will also stress a plant and could cause suckers to develop. Whenever planting woody plants sink them so that the level of soil in the pot they are grown in is level with the soil they are planted in.

Another reason for suckers or water sprouts is that plants are pruned incorrectly or too drastically. Seldom is it advisable to remove more than one-third of the plant at one time. Also, avoid topping ornamental or woodland trees.

Ideally suckers and water sprouts should be removed as soon as they are produced. Often, they can just be rubbed or twisted off in spring as their stem is just starting to expand. Once they reach pencil-size in thickness, cut with clean, sharp pruners. Do your best to remove them flush to a limb or as close to the tree’s trunk or root system as you can. Don’t leave stubs as these will likely have buds at their base and just regrow.

Speaking of suckers, there are often questions when growing tomatoes about what to do with the sprouts popping up where the leaf attaches to the main stem. Typically suckers just form on indeterminate tomato varieties, which are those that continue to grow, bloom and set fruit as long as growing conditions allow.  If all suckers are left on the plant, it becomes quite unruly and hard to stake. Also, fruit will be plentiful but usually smaller.

Usually, the suckers below the first fruiting cluster are removed so the development of those tomatoes won’t be slowed. Then it is up to individual gardeners to decide whether to leave suckers or not and how many to leave. Often a few are left to increase and extend the harvest. Tomatoes in our area are prone to many leaf diseases, especially during humid and wet seasons. As the bottom leaves yellow and die, it is beneficial to let some of the suckers on top grow so plants can produce more foliage to yield food for the plant and to shade the developing fruit. Some experimentation might be necessary keeping in mind that it is better to remove too little than too much.

For questions about pruning suckers and water sprouts 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.

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By Dr. Matthew Lisy, UConn Adjunct Faculty

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.

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.