When and why to prune and harvest locally in the growing season.
While our vegetables, herbs, and fruits are growing throughout the season, gardeners often find themselves hesitant to prune or even harvest.
Fear of taking the shears to any greenery stems from the concern over killing, disfiguring, or impacting fruit and flower production — all reasons to think twice before grabbing the loppers. Yet many trees, shrubs, perennials, annual flowers, and vegetables need a visit from the barber for their health. Taking the ultra-conservative approach of doing nothing actually can cut short the activity or life of the plant or tree.
The multiple local resources and research on best practices can help home gardeners overcome fear and analysis paralysis to have the most proliferative and healthy landscapes.
Annual Vegetables and Herbs
“Harvesting regularly is the best way to prune herbs,” says Lyndsey T. Langsdale, board president of Reno Food Systems and manager of its Park Farm.
In the heat of the summer, a plant wants to reproduce before it dies, so it sends up a flower that will go to seed. All is not lost. For example, most basil plants have colorful and interesting flowers that attract pollinators. If flowering happens on herbs, continue to trim the youngest leaves for the best flavor by removing the top sections of main stems, to prevent flowering, until it completes its yearly cycle.
“Mint in the spring has this really beautiful, soft, and delicate texture. As it gets hot, it gets more coarse. The flavor is still pretty much the same, and it’s going to be just as nutritious,” Langsdale says.
To extend the life of cooler weather leafy greens such as kale, chard, and heat-tolerant varieties of lettuce, using the cut-and-come-again method encourages more growth and may also stave off the bolting process through the warmer months.
Some varieties of warm-season vegetables, such as tomatoes and squash, can benefit from pruning for fruit size, disease, and pest resistance. Rachel McClure, Washoe County Master Gardener coordinator, recommends pinching off the suckers, or shoots that appear in the junction between the stem and a branch, of a tomato plant, particularly at its lower parts. This helps the plant to send more growth into existing stems and fruits, increasing production and fruit size.
In our area, powdery mildew and squash bugs are a common problem for cucurbits. Cutting off leaves with bug infestation will decrease the pest pressure, but not eliminate them.
“Removing diseased leaves can help the plants,” McClure says. “If you’re trying to grow a really large variety of pumpkin or squash, you could prune out any competing fruit to put all the energy into that fruit.”
Shrubs and Perennials
Know when flowering trees and woody shrubs bloom and whether flower buds form on old wood or new wood.
“Lavender, culinary sage, and rosemary are great examples of plants that you would prune in June or July … A lot of your pruning is just harvesting flowers or deadheading the plant so that it grows more tissue,” says Neil Bertrando, owner of RT Permaculture in Reno.
Depending on the variety, some plants may rebloom in the fall after pruning; however, many gardeners leave the spent blooms for bird and insect food.
Trimming Trees
Trees can be trimmed any time to reduce weight and eliminate dead or compromised branches, but heavy pruning should be done during the dormant season.
“The most important thing anyone can do for their trees in Nevada is to water them more than pruning, more than fertilizing. Yes, you can overwater your trees, but in the heat of the summer here, it is very difficult to do,” says Noah Silverman, owner of Noah’s Park Tree Care in Reno, adding that if you’re concerned about breakage on limbs laden with fruit, “[t]he best course of action is to thin the fruit. Don’t thin the structure of the tree.”
Keys to Pruning
- Sterilize your tools between plants to prevent the spread of disease.
- For trees, schedule a summer health check from a licensed arborist, and plan on heavy pruning in the dormant season.
- Contact your local cooperative extension office/master gardener for handouts and classes on pruning specific to your area.
- Invest in a horticulture book or respected resource to learn proper pruning techniques.
RESOURCES
Master Gardeners of Washoe County
775-784-4848 · Extension.unr.edu/master-gardeners/washoe.aspx
Noah’s Park Tree Care Service
775-376-0917 · Noahsparktreecare.com
Reno Food Systems
775-815-1113 · Renofoodsystems.org
RT Permaculture
775-830-8822 · Rtpermaculture.com
