As spring plant sales start cropping up and these three herbs become available as starts, or you see seeds in local stores, here are a trio of tips for growing and maintaining these tricky triplets during the summer.
1. Sow seeds in late spring, then successional seed planting as needed. Late spring really means late May or early in June. Soil temperatures should be in the 50 degree range which means it will feel warm when you touch it.
Basil starts transplant fairly well and will go in a container well. Be sure the pots of basil that you are setting out have been acclimatized well before planting. Set them in a protected area for 4-7 days to help the plants adjust to being outdoors. Some growers may have already done this, so check with them. Basil likes direct sun so find a sunny spot for it. Here in the PNW we plant it usually in early June
Cilantro (the leaves of the coriander plant) does best when directly seeded in the ground. If you want the seeds (coriander) you should plant seeds in late April or May (of a typical PNW year). In order to get the seeds to ripen the plant will need a long growing season. The feathery foliage that looks somewhat like parsley is cilantro and can be planted later in the spring. It likes the sun, too and could easily grow next to basil.
Dill doesn’t consistently transplant well, so direct sow the seeds where you want them. Dill should be in a sunny area, too. If you leave some seeds on the plant, they will fall to the ground and you’ll have dill again the next year. We usually wait for it to get a bit warmer before we plant dill - very similar to basil, maybe a week or two earlier at most.
So we usually seed cilantro first, followed by dill, and then finally basil.
Consider carving a bit of space in your garden for these three annual herbs. Depending on how much of each herb you would like, a 2' x 4' rectangle provides a good amount of space to provide enough of each herb for fresh use and some herbs for preservation (pesto anyone?). Simply scatter seeds across the area, gently cover with soil and then water in.
Basil grows to 12- 24 inches depending on the variety. There are dwarfs and mammoths and several exotic scented basils. Flower heads should be pinched off before they form. When the plants have 4 - 5 leaves, cut the stem off above a node where leaves join the stem. These side stems will produce another set of leaves which you can harvest in the same way and on into the fall when cooler weather will bring on brown spots and an eventual end to this year’s basil. If you want to save a plant or two for a winter window box do this before the plants begin to slow production. Transplant a few plants into pots and keep for winter use in a sunny window or under a light.
Dill has leaves and seeds that can both be harvested. The feathery leaves are called dill weed and are often used in cooking. The leaves have a similar taste to the seeds. The seeds are a must for pickles. The seeds form on a large umbrel head at the top of the stem. Smaller heads form on side stems but the large head on top is what is typically used for pickles. To save some for later use, cut the heads and store in a paper bag until dried, then store in a glass jar.
Cilantro/Coriander has leaves and seeds, too that can both be harvested. The lower flat, scalloped leaves are the cilantro. Pinch off just as with the basil for continued production. These leaves are familiar in salsa and other Mexican dishes. Newer leaves near the top are lacy and eventually tiny white flowers will form on the top of the stem. These will mature into round seeds which can be harvested just like dill. This will be coriander. It is a common ingredient in curry powder and pickling spice.