Pruning丨Behind the Seeds

Welcome back to Behind the Seeds! This week, we will be looking at pruning! 

Before coming to Brookgreen, I thought that trees were trees and plants were plants. Sure, I knew about oak, crape myrtle, fir, and palm trees. Of course, I knew about roses, daisies, lilies, and all the fruits and vegetables at my farmer’s market and supermarket. What I didn’t know was how to nurture these plants and keep them healthy. One of the great ways to keep plants healthy is through pruning!

In Lucy’s article from a few years back, we were shown that pruning is a normal process around the Gardens and in our neighborhoods. Today, I will be explaining the benefits of pruning and how you can start pruning on your own.

Plant Health

There are four main Ds you should look for when you begin pruning: Death, Disease, Damage, and Degrees. If a section of the tree or shrub is dead, you should absolutely prune it. When there is a disease, try pruning the diseased section(s) so that the section(s) without the disease can keep growing. Damaged sections of a tree or shrub should also be pruned to avoid bacteria and fungi from getting into these plants, leading to disease. Damage can also come from sections of the tree or shrub rubbing against each other and/or sections competing for space. When considering degrees, look at the sections of the tree or shrub that have weak angles (smaller than 45 degrees). These weak angles can be a major point for rotting down the road, so the sooner you can prune that angle, the better!

During my rotation with Lucy and Frank, the four Ds helped me so much in understanding the basics of pruning! While you’re pruning, there is actually a fifth D to think about as well: Decoration. How will the pruning you’re doing change the shape and size of your plant? What changes will you have to make the tree or shrub fit your space? A great way to implement all five Ds is to do a Compass Test of the plant you are trying to prune! 

Compass Test

1. Pick the section of the tree or shrub that you want to prune.
2. Using the five Ds, think or say out loud why you want to prune that section.
3. Now, look at the section from north, south, east, and west. Visualize what the plant would look like without that section from each direction.
4. If you believe the section should be removed after looking from all four directions, then it is time to remove the section! If you do not believe the section should be removed, explain why. Common reasons to not prune would be that the cut would make the tree or shrub look uneven and the section looks great from other directions.

Pruning can truly change the life of your tree or shrub! By removing the four Ds, more sunlight can reach all areas of the plant, helping photosynthesis. Removing the four Ds can also increase air circulation within the tree or shrub.

When you are pruning, you promote healthy new growth, increase flowering, and increase fruit production! You are also maintaining the desired shape and/or size of your tree or shrub by pruning.

Another way to maintain shape is through limbing up, which is removing lower branches. If the tree or shrub is in a high-traffic area, limbing up can help the plants on the ground receive more sunlight and can allow more clearance to humans, animals, and vehicles. Increasing clearance can lower the risk of damage to the plant, humans, animals, and vehicles. 

Personal Health

The health benefits of pruning for humans are enormous! At the end of the article will be resources for you to read through if you’re interested and these resources will be cited in the article. The most obvious health benefit is that pruning (and other horticulture activities) are exercise. Across the world, horticultural activities have been shown to improve mental and physical well-being (Chan et al, 2017; Detweiler et al, 2012; Makizako et al, 2015; Tu et al, 2020; Ya-Fang et al, 2017; Zhang et al, 2017). Horticultural therapy has been utilized in older populations for successful aging, improved intimate relationships, and greater social connections (Chan et al, 2017; Han et al, 2018; Martin et al, 2008; Ya-Fang et al, 2017; Yang & Wen, 2020). Even just being in nature can lower your risk for depression and improve your mood (Bratman et al, 2015; Zhang et al, 2017).

As you learned earlier, when you prune a tree or shrub, you’re increasing the sunlight in and air circulation of the plant. If the tree or shrub is near a window, then more sunlight and air can come through your window. Having great access to sunlight improves the production of vitamin D in your body! Higher levels of vitamin D have been shown to increase bone mineral density and reduce the number of falls elderly people may experience (Mead, 2008).

No one wants to have a tree falling on themselves, their house, or their vehicles. When you properly prune your trees and shrubs, you avoid this harm! By removing the possibility of a fallen tree or large branch, you are also reducing your stress levels by keeping you and your loved ones safe.

Now that you know all the ways that pruning can keep you and your plants healthy, here is how you can start pruning!

Practicing Health

In order to get started, you’ll use four main tools: bypass hand pruners, loppers, a pruning saw, and a ladder. Bypass pruners are like scissors for trees and can cut ½”-1” branches. Loppers are longer pruners for 1”-1.5” branches that may be farther away. Hand saws are for 2+” branches. Below are some tips to get you started from myself and the Horticulture Department!

1. Never cut more than ⅓ of the entire tree or shrub at one time. Too much pruning can stress out your plant, making it more susceptible to disease and death.
2. When using the bypass hand pruners and loppers, keep the pruning blade closest to the bottom of the branches you’re cutting. This will help you make cleaner cuts and cause less stress to your plant when it is healing.
3. Always make two cuts when using the saw! The image above shows the two placement cuts I made before fully sawing. Both of these placement cuts go ⅓ of the way into the limb. The uppercut is a rough cut and is made to get a majority of the weight off. Lower down, the second cut is called an undercut and serves two purposes. The first is to prevent the bark from tearing when the rough cut is completed. Second, the undercut is used to make the area of removal smooth, which will help the plant while it heals. 
4. When your saw is stuck, don’t be on edge. Make a wedge! If your saw gets caught in a cut from the weight of the limb, you can slowly wiggle the saw out and try the wedge method. You’ll make a diagonal cut above the cut you were originally making (image above) and saw diagonally until the wedge piece comes out (image below). From there, you can go back to the original cut and finish sawing through!

Thanks for joining me for this week’s Behind the Seeds! Now, grab some pruning tools and let's keep our PHs balanced!

References

Bratman, G.N., Hamilton, J.P., Hahn, K.S., Daily, G.C. & Gross, J.J. (2015). Nature experience reduces rumination and subgenual prefrontal cortex activation. Proceedings of the National Academy of Sciences - PNAS, 112(28), 8567–8572. https://doi.org/10.1073/pnas.1510459112 

Chan, H., Ho, R., Mahendran, R., Ng, K., Tam, W., Rawtaer, I., Tan, C., Larbi, A., Feng, L., Sia, A., Ng, M., Gan, G., & Kua, E. (2017). Effects of horticultural therapy on elderly’ health: protocol of a randomized controlled trial. BMC Geriatrics, 17(1), 192–192. https://doi.org/10.1186/s12877-017-0588-z

Detweiler, M., Sharma, T., Detweiler, J., Murphy, P., Lane, S., Carman, J., Chudhary, A., Halling, M., & Kim, K. (2012). What Is the Evidence to Support the Use of Therapeutic Gardens for the Elderly? Psychiatry Investigation, 9(2), 100–110. https://doi.org/10.4306/pi.2012.9.2.100 

Han, A., Park, S., & Ahn, B. (2018). Reduced stress and improved physical functional ability in elderly with mental health problems following a horticultural therapy program. Complementary Therapies in Medicine, 38, 19–23. https://doi.org/10.1016/j.ctim.2018.03.011 

Makizako, H., Tsutsumimoto, K., Doi, T., Hotta, R., Nakakubo, S., Liu-Ambrose, T., & Shimada, H. (2015). Effects of exercise and horticultural intervention on the brain and mental health in older adults with depressive symptoms and memory problems: study protocol for a randomized controlled trial [UMIN000018547]. Trials, 16(1), 499–499. https://doi.org/10.1186/s13063-015-1032-3 

Martin, L., Miranda, B., & Bean, M. (2008). An exploration of spousal separation and adaptation to long‐term disability: six elderly couples engaged in a horticultural programme. Occupational Therapy International, 15(1), 45–55. https://doi.org/10.1002/oti.240 

Mead, N. (2008). Benefits of sunlight: a bright spot for human health. Environmental Health Perspectives, 116(4), A160–A167. https://doi.org/10.1289/ehp.116-a160 

Tu, P., Cheng, W., Hou, P., & Chang, Y. (2020). Effects of types of horticultural activity on the physical and mental state of elderly individuals. International Journal of Environmental Research and Public Health, 17(14), 5225–. https://doi.org/10.3390/ijerph17145225 

Ya-Fang Yao, & Kuei-Min Chen. (2017). Effects of horticulture therapy on nursing home older adults in southern Taiwan. Quality of Life Research, 26(4), 1007–1014. https://doi.org/10.1007/s11136-016-1425-0

Yang, Y., & Wen, X. (2020). Influence of exercise and gardening activity on successful aging: a six-year cohort study: 3016 May 29 2:45 PM - 3:00 PM. Medicine and Science in Sports and Exercise, 52(7 Suppl), 841–841. https://doi.org/10.1249/01.mss.0000684580.61554.43 

Zhang, G., Poulsen, D., Lygum, V., Corazon, S., Gramkow, M., & Stigsdotter, U. (2017). Health-promoting nature access for people with mobility impairments: a systematic review. International Journal of Environmental Research and Public Health, 14(7), 703–. https://doi.org/10.3390/ijerph14070703