September and October can be some of the most rewarding months for a gardener. Plants are fully grown and pumping out as many fruits as they can before the first frost. It’s like they know their time is up.
But it doesn’t have to be the end for some plants if you know how to help them out, according to Tony Cirian of Cirian’s Farmers Market on 50th and Leavenworth. Most herbs, for example, are as simple to grow indoors as they are outside. So if you’ve developed a taste for fresh basil on your tomatoes or tarragon in your scrambled eggs, don’t despair the coming winter. These tips will keep you in fresh herbs no matter the cold:
- Let annuals go to seed. Annuals, such as basil, cilantro, chervil, borage, and dill, are going to seed by now (and probably have been ever since temperatures started soaring). Collect the seeds and plant them in pots right away. Set the pots inside under a grow lamp or in a very warm windowsill. Keep them just moist until you start to see shoots.
- Salvage smaller mature annuals. Dill, cilantro, and chervil are too tall to transplant easily and probably don’t have many useable leaves left anyway. Cirian says that you can pot up smaller annuals such as basil and parsley (actually a biennial) if they still have leaves to harvest; they’ll last a bit longer if you bring them inside, but they will die eventually. “You might get an extra month or so out of them,” he says. But by that time, the seeds you planted will have germinated. You’ll only have a small gap, if any, without fresh herbs.
Know the needs of your perennials. Perennials are essential additions to an herb garden, but they can vary in their care:
- Rosemary, for example, is technically a tender perennial but isn’t usually hardy enough to endure our Zone 5 winters, according to Cirian. You can attempt to pot up the entire plant and bring it inside. Cirian does warn that the plant will get a bit woody and lanky over the winter. “It’s just not getting the sunshine and warmth to be really vibrant.”
- Tarragon is another perennial that benefits from potting up over the winter for extra protection. It can be handy to divide a root clump, leave a few plants outdoors, and just bring one inside. (Note that Russian tarragon is unfortunately more commonly sold, though it tastes more like a weed than the licorice flavor of French tarragon.)
- Other perennials, such as chives, common thyme (thymus vulgaris), sage, oregano, and lavender, are easily left in place throughout the winter and will come back nicely next spring. To enjoy them inside as well, root thyme, sage, oregano, and lavender cuttings in pots. Keep the cuttings moist until you see new growth. You can add chives to your winter kitchen by digging up a clump and dividing into pots.
- Some perennial herbs can be invasive and so should only ever be grown in pots. A large pot of mint or lemon balm adds a fresh smell to your patio and can easily be moved inside before the first frost.
To make the most of your indoor herb garden, use potting soil (never garden dirt) and only water once a week. “You don’t want that root system to rot,” Cirian says. He adds that there’s not much need to fertilize over the winter, as “potting soil already has a slow-release food.” Just make sure light and warmth are in good supply, and that’s all it takes to keep yourself in fresh herbs all winter long.