Manage these 7 problems in your garden
This has been a tough year for many vegetable gardeners. Aside from the fungal issues we’ve faced due to our wet spring and early summer, I’ve been hearing from lots of gardeners about other disorders that have negatively affected their yields and the quality of their harvests. While more experienced gardeners know that bad years occur from time to time, we all want to do our best to make sure these problems don’t crop up again in next year’s garden.
The biggest challenge in overcoming problems in the vegetable gardening is learning to properly identify the issue and understand its cause. While many troubles appear to be fungal or pest related, they aren’t necessarily due to a pathogen or insect. Instead, the issue may be the result of something in the plant’s environment, rather than a disease.
These types of problems are known as physiological disorders. They can be attributed to things like sun scald, nutritional imbalance, drought, heat stress, frost damage, herbicide injury and other factors.
There are many different physiological disorders that can strike the plants in your vegetable garden, but here are a few of the most common ones I’ve heard about this season, along with some tips for keeping them out of next year’s garden.
Curled leaves: Leaf curl is a physiological problem often related to fluctuations in moisture levels. For many tomato varieties, curling up their lower leaves is a way to protect the plant from further moisture loss by protecting the pores on the leaf surface. Some tomato varieties are more prone to leaf curl than others. If the leaves are blemish-free, leaf curl on the older leaves isn’t anything to worry about. Mulch plants well at the beginning of the season to even out soil moisture levels, and make sure your garden stays well watered.
Cracked fruits and veggies: A physiological problem tied to moisture levels, skin cracking most often occurs just after a period of heavy rainfall, primarily after a prolonged period of dry weather. The plant uptakes water from the soil, and it collects in the developing fruits. The skin can only expand to hold the excess moisture for so long before it cracks open. Some vegetables are more prone to cracking than others, with tomatoes and watermelons being the most vulnerable. To avoid this problem, be sure the plants receive consistent moisture during dry spells.
Blossom-end rot: This disorder appears as a sunken, dark lesion on the bottom-end (or blossom-end) of the developing fruit. Tomatoes, peppers and eggplants develop blossom-end rot when there is a lack of calcium in the growing fruit. The trouble is not necessarily that your soil is calcium-deficient, but rather that the calcium can’t get into the plant. Calcium comes into a plant with water, and when plants are subjected to dry periods, the calcium cannot move into the fruits where it’s needed for proper growth. This leads to a calcium deficiency and blossom-end rot. The key to staving off this disorder is proper mulching and watering. Do not allow your garden to completely dry out between waterings. Consistent soil moisture is key.
No flowers: A complete lack of flowers on ornamental or vegetable plants could be due to too much nitrogen in the soil. Excessive nitrogen encourages green shoot growth at the expense of flower and fruit production. You’ll have a lush green plant with nary a flower or fruit in sight. Avoid using fertilizers high in nitrogen on crops that set fruit, such as tomatoes, peppers, squash, eggplants, melons and the like. Instead, opt for a complete fertilizer, if a soil test calls for one.
Hollow potatoes: If you slice open a homegrown potato and there’s a hollow spot in the center, it’s often due to environmental or nutritional stress. Periods of slow growth followed by periods of fast growth are often to blame. This growth pattern may be the result of heavy rains after a prolonged dry period or even a mid-season fertilizer application. To prevent hollow heart in potatoes, mulch the potato patch well and amend the garden with compost every spring, but skip the mid-season fertilizer. Make sure the garden receives consistent moisture throughout the growing season.
Deformed fruits and veggies or none at all: In order to produce fruit, most flowers need to be pollinated, and if there aren’t enough pollinating insects around, fruit and veggie production may not occur. Lack of pollination exhibits as the lack of fruit formation, blossom drop, or deformed fruits that are often puny and shriveled at one end. It takes multiple visits from a pollinating insect to form a cucumber or an eggplant, not just one. Do not use broad-spectrum pesticides in your vegetable garden, and encourage pollinators by planting lots of flowering plants side by side with your veggies.
Blossom drop or fruit drop: Young, developing fruits and/or blossoms are sometimes shed from a plant for a few different reasons. It may occur due to a lack of proper pollination or because the plant is stressed. Some plants do not set fruit when temperatures aren’t ideal. For example, bell peppers will abort their blossoms or young fruits when daytime temperatures rise above 90 degrees F and nights are warmer than 75 degrees F. They may also drop their blooms if temperatures are too cool. Daytime temperatures over 90 degrees F or nighttime temps below 55 degrees will limit tomato production, too. There isn’t much you can do about this disorder other than to wait it out.
Horticulturist Jessica Walliser co-hosts “The Organic Gardeners” at 7 a.m. Sundays on KDKA Radio with Doug Oster. She is the author of several gardening books, including “Attracting Beneficial Bugs to Your Garden,” “Good Bug, Bad Bug,” and her newest title, “Container Gardening Complete.” Her website is jessicawalliser.com. Send your gardening or landscaping questions to firstname.lastname@example.org or The Good Earth, 622 Cabin Hill Drive, Greensburg, PA 15601.