Question: I like to use basil right out of the garden for cooking, but it seems that my plants usually bolt by mid-summer. What can I do?

Answer: Flower formation (bolting) is part of the normal life cycle of a basil plant and is encouraged by warm temperatures, long days and drought. These environmental conditions stress the plant and cause it to shift from the production of leaves (vegetative growth) to the production of seeds (reproduction).

The problem is that when basil plants move into the reproductive mode, their stems become woody and their leaves turn bitter.

If a plant is just starting to set flowers, you can nip the problem in the bud — literally — by pinching off newly forming flowers. But once the flowers open, there is little that can be done to shift the plant back to predominantly vegetative growth. Your harvest of basil leaves will soon be over.

Prevention of flowering is the best approach to prolonging the basil harvest. Here are a few steps that can help.

First, choose basil varieties that are known to be slow bolting, such as the Genovese varieties ‘Aroma 2,’ ‘Everleaf,’ ‘Prospera,’ ‘Rutgers Devotion’ and ‘Rutgers Obsession.’ ‘Pesto Perpetuo,’ an upright, columnar basil with variegated leaves and a strong flavor, never flowers.

As temperatures warm, keep your basil plants well-watered. Add mulch around the base of the plants to keep their roots cool. If the plants are in pots, move them so that they are in shade during the warmest part of the day. If they are in the ground, set up a shade cloth or consider a taller companion plant that will shade the basil.

Harvest your basil frequently, cutting the stems to just above a set of leaves lower on the stem. Removal of the growing tips (not just individual leaves) delays flowering and encourages bushier plants.

If you cannot keep your basil in the vegetative mode, all is not lost. When flowers appear, harvest all the leaves and freeze or dry them for later use. Make sure the leaves, however, have not become bitter.

The flowers themselves are edible and add a basil-like flavor to dishes. Use them as garnishes in salads and in tomato-based sauces and curries. Taste the flowers before using them because they can be bitter.

Question: It’s the end of summer and one of my blueberry bushes (‘Spartan’) is blooming. What should I do?

Answer: ‘Spartan’ is a variety of the Northern highbush blueberry (Vaccinium corymbosum). Northern highbush blueberries typically flower only once a season. They initiate flower buds on new wood at the end of the summer and go dormant over the winter. They break dormancy in early spring and flower.

Depending on the variety and growing conditions, the berries ripen about 45-90 days later.

Under certain conditions, however, Northern highbush blueberries can flower twice in a season (a trait called “remontancy” from the French “coming up again”). In these instances, plants bloom as usual in the spring, but flower again in late summer. In virtually all cases, the second crop is negligible.

The exact mechanism that causes some blueberry plants to flower twice in a growing season is not well understood. Environmental stresses early in the growing season, such as a heat wave or drought, can initiate flower bud formation followed by dormancy.

After the heat wave or drought ends, the buds break dormancy and bloom just as if it were spring.

Genetics also plays a role. Remontancy is commonly observed among lowbush blueberries (Vaccinium angustifolium), a type of blueberry native to eastern and central Canada. In these colder climates, a second bloom has survival advantages because the first flush of flowers in spring is often damaged by late frosts.

Two relatively new blueberry cultivars, ‘Perpetua’ and ‘Echo,’ have been bred to produce two reliable crops of blueberries each year.

These varieties, both crosses between Northern highbush and lowbush blueberries, flower in early spring, producing berries in early summer.

They flower again in mid-summer, producing a bigger crop in late summer and early fall. The size of the two crops combined, however, is smaller than the one crop produced by a Northern highbush blueberry.

What should you do about out-of-season flowering? No guidance is available on how to respond to the late blooms. It makes sense, however, to remove the flowers unless it is a lowbush blueberry or one of the double cropping varieties.

The berries on a Northern highbush blueberry are unlikely to ripen before cold weather sets in and the development of fruit in late summer might tax the plant that is, hopefully, setting flower buds to produce next year’s crop.

Jeanette Stehr-Green is a WSU-certified Clallam County Master Gardener.