Editor’s Note: This column last appeared on 1 May 2019.
What to do this week
It is tempting on a bright sunny day to get out to the garden and start to dig. A psychiatrist friend once told me that soil contains natural anti-depressants, which made a lot of sense to me. How many six year-olds playing in the mud look unhappy?
Nevertheless, especially with all this rain, it is important not to start digging your garden beds too soon. It will destroy the fragile soil structure and lead to compaction, which will make rebuilding the soil even harder. Sandy soils drain and dry more easily than heavy clay, and raised beds drain earlier than flat ground. This can be a problem in hot, dry summers but they do give you a jump on the season in early spring.
‘Mudpies’ By Ludwig Knaus, Walters Art Museum Public Domain via Wikipedia Commons
If you are unsure about your soil type, or whether or not it is dry enough to dig, you can do a simple squeeze test. Scoop up a handful of soil and squeeze it in your fist. If it falls completely apart, it is likely mostly sand. If it stays in a ball, try to squeeze it upward with your thumb to form a ribbon. If you can’t make a ribbon, it is loamy sand. Light-textured sandy and silt loams form shorter ribbons than do heavier silty clay and clay. At this point, you can add a little water to the ball and try to get a feel for the texture. See if it feels smooth and slick or gritty or a combination of the two. Together with the length of the ribbon that will give you an idea of where your soil is on the spectrum.
Don’t forget that all soil types will greatly improve their structure with the addition of compost, which will help with both water retention and drainage and facilitate nutrient availability. Heavy clay soils with good structure will still crumble easily when dry enough to work. Sandy soils will still hold some shape instead of turning to powder. Walking on garden beds or tilling when it is too wet will ruin your soil’s aggregate structure.
A problem we have in the Maritimes with our high rainfall is acidic soil. Acidic soil slows nutrient uptake and can also affect soil structure in clay. Adding garden lime is a good way to fix this and the spring (and fall) are ideal times to spread it, if you can do so without excessive walking on the cultivated ground. The water moving through the soil at these times helps to spread its goodness. And if you lime before you till, that helps to incorporate it. The calcium ions in garden lime actually help the tiny, electrostatically-charged particles of clay clump together and assist in making nutrients more bio-available to the plants. It is not a substitute for good organic matter but is an important member of the team.
You can often tell what is going on with your soil by the weeds that are growing, especially the perennials. Dandelions, for example, indicate a calcium deficiency and often heavy clay soil. I fixed this in my field with enthusiastic additions of lime and compost and immediately got a burst of chickweed which filled the weed niche and made me a little more cautious about adding fertility. Fortunately, chickweed is an annual that is relatively easy to control, unlike the dandelions.
Coltsfoot also indicates heavy soil, as do daisies and creeping buttercup. Horsetail, by contrast, is indicative of sandy soil as well as low lime. Mustards, henbane, bladder campion and sow thistles indicate a neutral or alkaline pH. I got an outbreak of sow thistles the year following an overdose of lime. When adding lime, it is better to add a little over a period of years rather than trying to bring up your soil’s pH in one go. It can shock the soil to raise the pH too quickly and will not give the beneficial microorganisms time to adapt to new conditions.
Coltsfoot by Ryan Hodnett CC BY-SA 4.0 via Wikipedia Commons
Generally speaking, unlimed new ground in the Maritimes takes three to four tons per acre to bring it up to the sweet spot for vegetable production of 6.2 to 6.8. This translates into about 6 or 7 pounds of lime per 100 square feet. But it is better to apply this over the course of three or four years. After that, it should be applied sparingly as needed. I always recommend using dolomitic lime if possible, since calcium availability is related to magnesium, and dolomitic limestone has both in the right proportions. You may need to order it in, though.
Wood ashes will also raise the soil pH, but should be used with caution as the alkali in it is very water soluble. It reacts quickly and leaches out quickly. If you have problems with knapweed, you may want to avoid it altogether since your soil already has excess potassium. Use no more than 2 pounds per 100 square feet.
You can use up the time waiting for the soil to dry by seeding your peppers and eggplants now. If you have a garden bed ready you can plant some spinach – this is ideal weather for it and you can just scratch over the seeds lightly. And seed some basil too, while you’re at it. Mine never leaves the greenhouse but my couple of dozen plants give me plenty of pesto for the year.
Market gardener, farmer, workshop leader, seed-saver, political candidate and mother, Michelle Smith has spent over 30 years coping with the challenges of our bioregion and in the process has built a store of practical and technical knowledge. The Inverness resident has served on the board of Seeds of Diversity Canada and represented Alternative Producers with the Federation of Agriculture but can do nothing about her hair. She is pictured with a head of Club Wheat, a seed that shares her approach to hairdressing.
