I’ve talked a lot lately about fall vegetables, and written an extraordinarily long post about the king of summer, basil. But today I wanted to write a short and sweet post on three annual or biennial cool-weather herbs for the fall garden. (Well, as short and sweet of a post as I’m capable of writing…)
Now before we get started I do want to note that fall is a fantastic time of year for planting perennial herbs like thyme, sage, lemon balm, mint, and more. But that’s a post for another day. Today we’re going to talk about cool-weather lovers parsley, cilantro, and dill. All three (plus the bonus herb at the end) are members of Family Apiaceae, also known as the carrot or parsley family.
#1: Parsley (Petroselinum crispum)
Of the three herbs we’re talking about today, parsley is by far the most tolerant of hot weather–it can stay fresh and green all summer with a good, heavy mulch and moderate water. But it’s in its prime in the cooler weather of spring and fall. I find that its taste is also better in the cooler months; in the summer it can get a little strong and even acrid.
Parsley is a biennial, which means that it produces only leaves in its first growing season and then flowers and sets seed in its second season. (Well, except for this year, when some of my parsley started bolting in its first season…go figure.) So a parsley plant put in the ground this fall will produce only leaves until next spring, when it will start to flower.
Many people grow parsley as an annual and simply take it out before it flowers. But parsley flowers are very attractive to beneficial insect predators like ladybugs as well as flying pollinators–so if you have the space to leave it in the ground while it flowers, I highly recommend it.
Parsley is a hardy herb so it will continue to produce well through light frosts. I can usually expect a good harvest through late December, when I use a huge bunch of it to make my favorite herb & veggie dip for Christmas dinner!
Parsley can sustain cold damage in heavy frosts, however, so if you want a continuing harvest through the depths of winter you’ll need to protect it with heavy-duty row cover or cloches or grow it in a cold frame. Even without any protection, most parsley plants will survive the winter to flower in the spring due to their biennial nature.
#2: Cilantro (Coriandrum sativum)
In other parts of the world, the name coriander refers to both the leaves and seeds of this plant, but in the U.S. we call the leaves cilantro and the seeds coriander. Contrary to popular belief, cilantro is not a hot-weather herb. It prefers the cooler temperatures of spring and fall and is actually quite tolerant of the cold once established.
Cilantro is an annual, so it will produce leaves early on and then flowers and sets seed later in the same season. This bolting mechanism is triggered when soil temperatures rise above 75-80 °F–which happens early in our South Carolina summers.
If your heart is set on cilantro throughout the summer, sow frequent successions, mulch heavily around the plants, and situate them in a place where they receive only two or three hours of direct sunlight per day. Or you can let your cilantro bolt, collect the seeds, and use them to sow more plants or use them as a culinary spice or medicinal herb.
Fortunately, we don’t have to worry about that bolting mechanism when we grow cilantro as a fall crop. It thrives in the cooler temperatures of fall and, like parsley, weathers light frosts well. Also like parsley, it can sustain damage in heavy frosts so offer it some protection for continued harvests.
Overwintered cilantro plants not protected from frosts are occasionally tough enough to survive and flower in the spring, but more often than not I find that exposed plants will succumb to the cold.
#3: Dill (Anethum graveolens)
This is a weird one, I know–who grows dill in the fall when the cucumbers are long gone? But it is indeed possible as dill falls into the “cool-weather herb” category. (And it’s also possible to sow a late summer succession of cukes for fall harvest!)
Like cilantro, dill is an annual that produces leaves early on and then flowers and sets seed later in the same season. Also like cilantro, hot weather will prompt dill to form flowering heads earlier rather than later.
I actually don’t mind when my dill bolts because I get more mileage out of the flowering tops for pickles than I do out of the ferny leaves for cooking. But for those of you who prefer the leaves for culinary use, bolting plants can be frustrating. So if you plant some dill in the fall, you’ll have a longer window of opportunity for harvesting the leaves than you do in early summer.
You may read in books or online that dill doesn’t transplant well, but this is a bit of a half-truth. Dill doesn’t like to have its roots disturbed, so bare-root transplants don’t work well. But normal potted dill plants (1 plant per pot, please, to avoid having to divide them and disturb said roots) with good root systems in potting soil do just fine when transplanted into the garden.
Dill is more sensitive to cold than low-growing parsley and cilantro. If you offer your plants good protection they may survive the first few frosts but they are not hardy enough to survive long once winter really sets in. So enjoy dill leaf fresh in the fall and preserve some of your harvest dried, frozen, or in a preparation like herbed butters for winter use.
Recommended Varieties: “Dukat”, “Fernleaf”
Honorable Mention: Chervil (Anthriscus cerefolium)
Chervil is pretty obscure in America, though it’s a quintessential French herb with a lovely, delicate anise flavor. It pairs well with fish, chicken, and eggs. Like parsley, cilantro, and dill, it’s a cool-weather herb and a good candidate for fall gardening. I simply can’t find a spot in my spring and summer gardens where chervil will actually grow–no matter how sheltered, it just keels over in the heat. So I’m hoping to give it a try in the fall garden this year. I’ll let you know how it goes!