A fascinating and irreversible problem typical of many vegetable plants occurs when temperatures begin fluctuating in late spring. This phenomenon, often called bolting, indicates plants have started transferring more energy into reproduction and less into their edible parts. Once bolting begins, vegetables rapidly lose value as a tender and tasty food crop. Fortunately, bolting can be delayed, at least for a while
Common garden plants such as those in the mustard family like arugula, broccoli and cabbage along with lettuces, onions and cilantro grow best while temperatures remain consistently in the mid 60’s. The wide temperature swings of late spring cause these garden favorites to suddenly develop a tall flowering stalk and set seed. When this happens, they’ll often develop a tough fibrous texture and less appetizing flavor.
Any factors which cause stress in cool season vegetables such as heat, uneven watering, low soil nutrients or neglectful harvesting will lead to bolting. Gardeners can minimize the impact of a few stress causing elements by harvesting often. Watering regularly and fertilizing based on a soil analysis which identifies nutrient deficiencies. It’s the lack of regular harvesting that frustrates the efforts of most new gardeners.
West Texans shouldn’t necessarily wait for vegetables to reach the size typically seen in grocery stores before harvesting. Leafy vegetables should have their outer leaves gathered as often as they can be cut. Broccoli should be picked once heads have developed around three to four inches in width. Cauliflower heads can be removed as soon as they are six inches wide. Onions can be a little tricky but are usually ready for the table when their tops fall over. Once they develop seed heads, their bulbs stop growing and should be pulled up and used immediately.
Regular harvesting causes most cool season vegetables to continue putting resources into their edible portions and slows development of seed production.
To learn more about vegetable gardening in West Texas, contact the Texas A&M AgriLife Extension office at 686-4700 or email firstname.lastname@example.org.