Bolting Brassica

Toscano Kale, Bolting Winterbor
Flowering Mustard

It was 86 degrees today ... too hot for the early spring garden. Everything is bolting... the arugula, the kale, the collards. And now it's official - the overwintered cabbage will not be heading up this spring. It's bolting along with everything else.

Decorative Kale - Bolting

When plants form a seed stalk pre-maturely,  i.e. begin to flower, it's called "bolting." This can be a problem with spring crops. Most plants bolt due to hot weather. When the ground temperature rises above a certain point, the plant is prompted to produce flowers and seeds very rapidly, abandoning leaf growth almost completely.

Kale Bouquet
Tasty leaves removed!

Bolting is a survival mechanism in a plant. If warm weather threatens its survival, a plant will attempt to produce the next generation as quickly as possible. Why is this important? Once a plant has fully bolted, it is typically inedible. As energy reserves become focused on producing seeds, the rest of the plant tends to become tough and woody, tasteless or bitter. What is merely disappointing for the home gardener may prove to be disastrous for the professional farmer if plants bolt before producing an economic crop.

Occasionally, if you catch a plant in the very early stages of bolting, you can temporarily reverse the process by snipping off the flowers and flower buds. In some plants, basil for example, the plant will stop bolting and will resume producing leaves. In many plants, though, such as broccoli and lettuce, this step only allows you some extra time to harvest the crop before it becomes inedible.  So that's what I've been doing ... staying one step ahead of the bolt!

As I have documented in previous posts, the mustard bolted long ago.  It has already been harvested and what remains in the garden has now gone completely to flower. I won't hold that against it, though.  Its cheery yellow blooms brighten up the garden.

Warmer than normal conditions have mandated that I harvest my broccoli more "sharply" this spring, taking less-mature heads than normal.  The good news:  Even though the central stalks were smaller than expected at harvest, the plants are producing many delicious side branches.

I cut the largest leaves of the collard greens. They are such a rich, dark green color... you just know they're going to be good for you! I hope the smaller leaves will continue to grow in the next week or so without getting too bitter to enjoy.


I cut all the winterbor kale today. The leaves were green and gorgeous. One of the best things about gardening in the early spring ... no bugs! While the winterbor has bolted, the sturdy, dark green toscano kale is still going strong. Choice of plant variety does make a difference.

Some varieties of cabbage are more tolerant to heat than others.  The type I planted last fall obviously was not one of them.  I'm looking at complete crop loss this year.  Every plant is bolting.  The chickens will be feasting on cabbage for a good long time!

Cabbage is known to overwinter in most of the extreme eastern and southeastern parts of NC. But I have witnessed successful overwintering right here in Pittsboro. Perhaps a little success leads to hope beyond reason? Oh well, nothing gambled, nothing gained. I had $1 invested in a total of nine cabbage plants. It was worth the risk.  I'll have to look for these varieties next year, known for overwintering capabilities: 'Bravo', 'Green Cup', 'Rio Verde' and 'Conquest'.