Winter can be slow at Seattle’s Tilth Alliance, a farm and garden resource organization. In January, the hotline rang maybe 10 times a day. But by the time February is over, the calls come thick and fast, says educator Gavin Tiemeyer, as people consider where to plant their tomatoes or whether there is any sense in trying to grow watermelon in Issaquah.
But now, when the soil is too cool for planting just about anything, there are still things that you can do to get ready for the upcoming growing season.
1. Cull your garden.
Walk through your garden and determine what isn’t working. There may be shrubs or plants that are no longer appropriate for the space or that have outgrown their current location, says Tiemeyer. Those may be candidates to pull out or move. You can also tackle the weeds that are starting to pop up before they become a bigger project.
It’s a good time to prune woody shrubs like roses, lilac, or blueberries, and to trim your fruit trees.
2. Shop for bare-root trees and shrubs.
Tiemeyer notes that buying bare root is often cheaper, and they often adapt better to new conditions than planting a more expensive burlap-wrapped specimen with a root ball of soil from somewhere else.
3. Buy and swap seeds.
Seed companies like Territorial and Johnny’s generally send catalogs out in January. Whether you purchase from them or at a local store, do it early. Tiemeyer says that there have been seed shortages due to supply chain issues and the resurging popularity of gardening spawned during the COVID lockdowns.
If you have seeds from the last year or two that may still be viable, you can also ask friends and neighbors if they are interested in swapping. A recent seed swap event in the Brighton/Dunlap neighborhood in South Seattle attracted about 10 people who eagerly went through each others’ envelopes and baggies of seeds, taking what they wanted, giving what they had excess of.
4. Wait until the end of February to plant indoor starts.
You can buy supplies like peat starter pots, or grow lights and heating pads, although Sharon Coutts, a Duvall gardener who used to run a CSA from plantings she grew on an acre of land, says you don’t really need special products. She never used either lights or heating mats, “It depends on what kind of gardener you want to be. If you want to get the first radish or the first tomato, you will do things differently. I want to let the sun do most of the work. For me, that means a shorter growing season and less food. But that’s my rhythm.”
The one exception for early starts is anything in the allium family, Coutts says. Those can be started from seed and you can trim the tops (and use them in your food), and then set them out when your soil warms up. With other plants, early starts risk becoming leggy and are less likely to be hardy enough to survive outside if you start them too early.
When you consider which plants to start from seed and which to invest in starts, consider our climate carefully. Tiemeyer says starting things like tomatoes, peppers, basil and cilantro inside is asking for weak leggy starts by the time it’s warm enough to plant them out. Night temperatures for tomatoes need to be consistently above 50 degrees for them to do well, and that usually doesn’t happen before June. But if you have a greenhouse, you have more options.
5. Plan your planting.
We live in the Maritime Northwest garden climate, but there are many microclimates in the greater Seattle area. When you plant in Kirkland is different from when you plant in Renton, and that’s different from when you might plant in Seward Park, says Tiemeyer. Even at a single residence, you might have areas where the soil warms faster than other places. What you can plant outside when will depend on that.
Coutts says soil generally has to be above 50 degrees to allow for outdoor planting. Where she lives, that may be a full month later than in Seattle. “I learned the hard way not to do things at the first possible moment,” she says, recalling one unlucky potato crop she lost to a late frost in May. “Now I know not to plant root vegetables until I see the dandelions blooming.” Dandelions signal a soil temperature that is conducive to root crops, almost all of which need to be direct sowed, she explains.
A soil thermometer is a relatively cheap and useful tool to help you determine when to plant your starts or direct sow, Coutts says. Knowing that the soil has warmed up against that south-facing rock wall could mean you have fresh lettuce a couple weeks earlier than if you planted it in that bed out front by the mailbox.
You can also create your own warmer microclimate with floating row covers and cloches, says Tiemeyer. They can raise the soil temperature and protect starts from late frosts so you can get a jump start on your brassicas and greens.
When you consider where to plant what, think about crop rotation, too, he says. Planting the same thing over and over in the same place depletes the soil of the specific nutrients that kind of plant likes. It also makes it easier for diseases to take root. For example, brassicas like cabbage and broccoli can get club root, and if you have it one season and plant the same thing there the next season, you are asking for the same disease to strike. For tomatoes, it may be blossom end rot, and for members of the onion family, rust can be a problem. Some of these diseases can take years to leave the soil, Tiemeyer says.
Think, too, about companion plantings. For example, Coutts says that you can plant dill among your cabbages to prevent cabbage moth. Nasturtiums are known to dissuade aphids and can attract blackfly so it doesn’t attack other crops.
6. Amend your soil as needed.
Most people don’t get their soil tested regularly, but you can do so and find out exactly what your soil needs. If you are the kind of gardener who doesn’t want to work that hard, Coutts says adding compost every year can give you good enough soil for most gardening desires. “The goal is to build the soil. If you do that, you get the plants.”
Dig a good compost into the first few inches of your soil, says Tiemeyer. If you grew cover crops, turn it under now, and if you’re digging up grass to turn into garden beds, you can dig it up to a few inches below the root mass and turn it upside down to achieve something similar to digging in a cover crop.
7. Tread lightly.
The soil at this time of year is pretty water-laden, and Tiemeyer says that where you walk can compact it to the point of being too dense for roots to grow well. Walk in areas where you are not planning on planting, or loosen the soil again after you have weeded, dug in compost, or pulled up or planted a shrub.
8. Never stop learning.
Tiemeyer he says continues to learn about gardening simply by answering questions of hotline callers. For those who want to read up more on gardening, he recommends the Tilth Maritime Northwest Garden Guide, which you can purchase on their website. The organization also hosts classes and educational talks.
You can find a myriad of local Facebook groups related to gardening in the area, too. Search for words like “PNW gardening” or “PNW homesteading” “Seattle urban farmers” for options.
Coutts says one of her favorite books on companion planting is Carrots Love Tomatoes.
If you have setbacks, try again. Remember, Tiemeyer says, no gardener ever knows everything.
Lisa Jaffe is a freelance writer in Seattle. Follow more of Lisa’s work here.