This post will help you figure out for yourself what to sow now for your fall garden: veggies, herbs and perennial flowers. It does not have, I’m afraid, another one of those lists of “what to plant this month.” A simple search will give you many such lists that say more or less the same thing, and they're a good place to start. I can’t add much to the genre, but being a first principles sort of gal, I can help you understand some of the reasons behind planting and timing so you can choose what works best for you.
The main limitation of the “what to plant now” lists is that everyone’s local climate is different, and our planet’s overall climate is changing. What works in New York doesn’t work in California, and what worked in 1995 might not work now. The first step is to pay attention to your climate, and to how it's changing.
Even without climate change, every year is different, and it can be a good idea to make multiple sowings a few weeks apart, bracketing your “ideal” planting date, because you never know when you’ll get an unexpected heat wave or frost. A market gardener I know from Marrakesh, Morocco told me he sows all his vegetable varieties every 2 weeks, year-round because his weather is so unpredictable. That way at least some of the crops make it.
For most of us, the climate isn’t that extreme, but the windows within which to plant various plants are really quite wide.
If you take just one thing from this post, I hope it’s confidence to try sowing seeds at times other than the “perfect” ones. You really never know what the weather holds.
Days to maturity
Most seed packs will tell you the number of days to maturity, or harvest. Sometimes they mean days from transplant, and sometimes from seed, which can be confusing, so read carefully. Those numbers are also calculated under ideal conditions, which of course doesn't apply if your conditions aren't ideal.
Once, as a beginner gardener, I planted carrot seeds in December. Seeing the “60 days to maturity” on the packet, I thought I’d get carrots in February. Turns out, carrots (like most plants) barely grow in mid-winter, and I got my harvest somewhere around May. Take the days to maturity more as a general guide than what will actually happen.
That caveat aside, the approximate time to maturity is helpful because you can look ahead to when you’d like your harvest, and work backwards. For example, if you want brussels sprouts for Thanksgiving, and they take 110 days from seed, you’d plant your seeds on August 8th.
But because climate is variable, and things happen, if you REALLY want brussels sprouts for Thanksgiving, I’d plant a batch on July 25th, August 8th, and August 22nd.
If, on the other hand, you don’t really care when you get your brussels sprouts, but you love them, and want to make sure you get lots, you could sow every 2 weeks from June through October, and see what happens.
Categories of plants for this time of year
So, not a plant list, per se, but some categories that will help you think about what to plant now.
All members of this family, from broccoli to kale and arugula to bok choi grow best in cooler weather, which for most climates means fall and spring. The conventional wisdom is that they prefer a warm start and a cool finish, making them the classic fall crop. The longer maturing varieties, like broccoli and brussels sprouts should be started sooner, and the faster ones like arugula should be started later.
Pretty much any leaf you like to eat comes out better grown in cooler weather. Even those that are heat tolerant (like collards and some lettuces) are happier when it’s cooler.
With the exception of basil (which really needs heat to thrive), most common herbs do well in fall: cilantro, parsley, dill, chives, scallions (aka bunching onions).
Rudbeckias from seed I collected last year
In most zones, fall is the best time to plant perennials. Their roots can grow and establish over the winter and be ready for vigorous top growth and profusions of flowers next summer.
If you’re thinking of putting in some perennials in October, now is a great time to plant the seeds and save yourself some serious $$. To make a full-looking display, you might want 10 plants each of 5 varieties, which could easily cost $200 - $300. In comparison, seeds are really inexpensive!
These are seeds I collected just on a morning's walk a few days ago, all of them from plants escaping their gardens into public space, into roads or over sidewalks.
Nigella is one of my favorite seed heads
Or to be extra thrifty, while also researching which varieties will work at your house, you could have a walk around the neighborhood and collect seeds to take home and plant. Mind you, I’m not suggesting you wander through neighbors’ gardens stealing seeds. But once your eyes are open, you’ll see seed heads, brown and forlorn, dangling over the sidewalk and in other public spaces, everywhere you look.
Rudbeckias from seed I collected last year
Last year I saved seeds from a sunflower growing in the cracks in the pavement, and some rudbeckias barely hanging on at the edge of a road. Those tough survivors were strong and well-adapted, and their seeds have grown into vigorous plants.
Cuttings of perennials
Now is also a great time to take cuttings of perennials that you’d like to multiply. If you have one lavender you like, but you want 10, take cuttings now to have baby plants ready to plant out in October. Here’s a post I did on using Orta pots for cuttings. (The same method applies for regular pots. You just have to water more.)
What are you planting now? And what are you planning for fall?
If the cuttings are rotting, you probably have a soil blend that holds too much water. I’d try adding some grit (sand, perlite, pumice) to give it more drainage. The key with cuttings is to keep them moist, but not too moist. Because your Orta pot will always give a consistent amount of water, the way to adjust the moisture level is to experiment with how well your soil mix drains or holds water. Success also depends quite a bit on the type of cutting. Succulents, for example, need to spend a couple days drying out and forming a callus before being rooted or else they are prone to rotting. Roses on the other hand, do well with the base of the cutting moist and the top in a plastic bag to prevent drying out. Finally, keep in mind that cuttings are fickle, and even really experienced gardeners loose a lot of them!