Gardening with Dave Allan: How to Start Early to Peak Crops

If you’re a regular on “Grow Your Own” or have been inspired to grow some of your own fruits and vegetables during the pandemic, an early harvest is always welcome. But only try crops that are likely to be successful.

As I write this towards the end of January, the soil temperature in my garden was a measly 3℃. It will slowly warm up, but only overwintering plants could survive, let alone thrive, in such cold soil. So we have to warm up the soil for new plantings.

I confess that I was so keen to get into the garden that I tried to bring beans and snow peas into the greenhouse in January to plant them at the end of February/beginning of March. But the low sun caused the poor seedlings to grow very slowly. A second sowing a month later was much better. I got more good plants and the crop was ready to harvest around the same time as the first one.

I had learned the hard way that plants only work well when they grow steadily and the conditions are right. They never recover if controlled by too low or scorching light, fluctuating temperatures, and over or under watering.

So be patient for another 2-3 weeks. Put the pea and bean seeds in a saucer of water for 24 hours and cover with a damp kitchen towel. Then sow in biodegradable pots, using homemade compost or peat-free multi-purpose compost and bring it to a greenhouse or on a windowsill until the plants are big enough to plant out.

Prepare the plants for the outdoors by “hardening them off”. This means taking the seedlings outside during the day and bringing them back at night for 7-10 days.

Spinach and Swiss chard are also worth trying in a few weeks. You can sow directly in the ground in March but, again, you will get faster results by sowing in moist compost indoors. Because each ‘seed’ is actually a capsule containing several seeds, sow very thinly, either in a seed tray or in a pot like I do. Lettuce, oriental greens, arugula and others can also be treated in this way for planting under cloches.

Small root crops such as white turnips, beets and small, fast-growing carrots like the Paris market should be sown directly in warm open ground.

Even fava beans, the toughest plants I’ve mentioned here, need a soil temperature of at least 5℃, so use a cloche to warm the soil first. Although I don’t recommend digging over a bed, loosen the top layer of soil to aerate the soil, allowing it to warm up faster. I find a cultivator acts almost like a rake, but a rake would be nice.

Then cover the bed with a bell made of strong clear polyethylene or clear plastic sheeting. We don’t have a realistic alternative to plastic for this, I’m afraid. There are many size, shape, and price choices online, ranging from simple to elaborate.

If the cost of small enough bells infuriates you, why not make your own. Buy a roll of transparent plastic large enough to be at least 30 cm above the ground. Buy square or semi-circular hoops and build the bell size you want.

The blanket should not rest on the ground as we need air to warm the ground inside the cloche and the further it is from the ground the more effective the cloche will be. Fleece protects plants against wind and pests, but does nothing for temperature.

Leave the bell in place for 2-3 weeks and weed any grass flush. On sunny days, spread the plastic to prevent overheating.

Plant of the week

Iris reticulata ‘Gordon’ is an early flowering dwarf iris with blue stems and purple sepals streaked with yellow. Although entirely hardy, it is best grown in a pot to ensure good drainage and kept in a sheltered location to protect the flowers from driving rain.

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Terri S. Tomasini