TWIG (“This Week In the Garden”) posts will appear weekly, on Mondays, to help you know what to focus on for a successful growing season.
This Week in the Garden (TWIG #1)
April 20, 2020
It all starts with the soil
Peter Heffelfinger
If you are new to gardening this year it is important to remember that everything begins with your soil. While Fidalgo Island is blessed with a moderate climate for year-round vegetable production, there are challenges in finding a good garden site.
The first few gardens I had here lacked any real layer of topsoil, the healthy, friable layer of dark dirt that is the basic need for growing a crop. Due to the Ice Age glaciers and various former river beds, we have layers of gravel and clay or concrete-like hard pan that can lie right under a layer of regular soil. In the worst scenario, one needs to build an enclosed raised bed filled with new topsoil. It is vital, though, that the hard sub-soil be loosened up first with a spading fork to provide good drainage. Soggy soil means poor growth, more pests, and eventually dried-out unbreakable clods. Note: do not invert the gritty subsoil to the top layer; keep it at the bottom, underneath the topsoil.
I rake up the available dirt into raised beds 6-8 inches high to warm up the soil in spring and to drain better in the winter. It is important to regularly add composted organic matter to keep the soil loose for aeration and good tilth. Note: compost alone does not supply large amounts of balanced nutrition to your plants. Amendments are needed, whether from well-rotted manure or organic commercial mixes. I use a combination of both. In addition, given that our native soil is acidic, a dusting of slow-acting dolomite lime (not fast-acting industrial lime that may burn your plants) is also required (except where you plant potatoes, which prefer acid beds).
Given that we are well into spring, I would concentrate on planting early, cool-weather crops, such as lettuces, radishes, and greens such as spinach and Bok Choy, which will readily go to seed in summer heat. Once the soil heats up in early to mid-May, it is time to plant beans, squash and other warm weather varieties. I hold off on corn until June 1st. For tomatoes, peppers and cukes I use a grow tunnel for added heat during our cool night mists that roll in off the Sound. We are in a maritime climate, even as our summers get warmer and drier.
Thank you, Peter, I’m so happy to have a series of steps to follow each week. A few questions – which veggies have the least water requirements, and how do I know if I’ve over or under-watered.
Thanks for sharing your expertise.
Hi Robbie,
It’s hard to say which vegetable needs less water, since they all need regular watering in order to produce a crop. This is especially true given our Mediterranean-style dry summers, which are getting drier and longer in duration due to climate change.
I know corn, if you have space for it, needs a lot of water. I would say potatoes as well require irrigation, which is why you see the watering jets going full blast all summer on the potato fields on the Flats.
Any small, quick spring crop such as radishes will stay small and hard if not watered well. Water stress is signal to a plant to go to seed right now instead of waiting until it is fully grown. Lettuce that lacks watering will taste bitter rather than sweet or juicy. Water makes up a large percentage of the overall mass of any vegetable, so it is critical to keep the watering going throughout the life cycle of the plant.
To reduce the amount of water needed it is vital to have good soil that will absorb and retain water as long as possible, but without drowning the plant in standing puddles. Organic matter such as compost is a much-needed addition. You can also try a light mulch, but I avoid that due to slugs and snails that will hide beneath the mulch during the day but come out at night to dine on your plants.
As for knowing how much to water, you need to have the water penetrate at least 1-2 inches below the top crust. As a general rule it is better to water deeply every 2-3 days, depending on the weather, rather than a light spray daily that doesn’t really get down to the roots. To save on water loss from evaporation, water early in the morning, before the heat of the day. Also, if your leafy greens start to wilt a bit, it means they didn’t get enough earlier in order to get through the afternoon sun.
Hope these suggestions help.
Peter H.
Thank you. This is just what I needed. I think I’ve been too inconsistent, and stingy, with my watering. Hopefully this year’s crop will be the best.
Hi Robbie,
The best way I know of to keep watering to a minimum is to mulch your garden beds. It significantly reduces the need for water, keeps the soil workable, keeps the weeds down, fosters strong plant growth, and helps your soil retain the CO2 that it captures through your plants. Mulch does encourage slugs and snails, as Peter mentioned, but I’ve found that I can easily control these by doing some nighttime slug hunting early in the season. It sounds silly, and it can be kind of gross, but it really works!