Helpful tips for planting a summer herb garden

By Viva Mertlich
WSU Chelan/Douglas County Master Gardener

Lush Basil against a black background.
Basil is a popular herb to grow. If you’re new to growing basil, be sure to plant it in a spot in your garden that gets full sun or in a container situated to get full sun. – Pixabay/ulleo
Viva Mertlich
Viva Mertlich – WSU Extension Chelan/Douglas County Master Gardener

There is almost nothing as wonderful as the aroma and flavor of fresh herbs on your plate. It is easy to start and grow a summer herb garden, and it is one of the most rewarding edible gardens you can grow.

Herbs do well in containers or in the ground, but they all need lots of sunlight to thrive. Just like a vegetable garden, you should plan for your herb garden to get a minimum of six hours of direct sun per day, and make sure you have healthy soil with good drainage. There are some herbs, such as cilantro, parsley and mint, that will tolerate or be more successful in part shade.

As a rule of thumb, herbs should be planted after the last frost in spring. Although some herbs — rosemary, parsley, sage, cilantro and mint — are hardier and can be planted earlier, most new plants will get off to a better start if planted when conditions are mild and conducive to growth.

Cilantro is a short-lived plant and can do well when planted earlier in spring, or even later in fall, if there is enough time before freezing weather to get a crop. Once cilantro bolts — sends out flowers and goes to seed — the leaves turn bitter, and a new crop begins; the dried seeds are called coriander. Cilantro bolts after eight to 10 weeks in the garden and when the roots of the plant get above 75 degrees. Salsa lovers may want to plan several staggered plantings of cilantro during summer.

Basil, like cilantro, is a leafy herb often used in copious quantities, such as for making fresh Italian pesto. Successive plantings for several weeks can give you a long and delicious season of this herb as well. Basil needs full sun to thrive.

Rosemary or mint may grow quite large and last well into early winter, when all the other fresh herbs are long gone from your yard. Be careful planting any type of mint; it is a very invasive plant and can be difficult to contain or eradicate. Many gardeners choose to grow mint in containers for that reason.

Most herbs are minimal maintenance in the garden and require low water, once established. When planning garden placement, do not forget that afternoon shade for your cilantro, parsley and mint will keep the plants from overheating and drying out during the sweltering summer months. Herbs can be sown early indoors from seed (follow directions on seed packets) in a south-facing window or with grow lights, or easily purchased in spring as small plants from garden centers around the valley. Be sure to check out the annual Master Gardener plant sale at Pybus Public Market on April 29.

Due to the relative ease of growing them, satisfyingly rapid growth of most herbs, and the flavor and healthy qualities they can add to your culinary delights, it may be worth growing an herb garden this summer.

Herbs are beautiful plants that can also add interest to your garden, and many are disliked by deer and friendly to pollinators (if you forget about them and allow them to flower). Feel free to mix your herbs into other areas of your garden or grow them in their own dedicated area; just make sure to be especially safe and thoughtful about any chemical treatments in or near an edible garden. Follow label directions for any chemicals used in your landscape.

More detailed information on many favorite herbs, and ideal growing conditions of each can be found on the WSU Extension King County Master Gardener website, bit.ly/tipsheet8.