With spring unfolding so slowly (some of us only recently stopped having snow showers!), there may still be a few frosty mornings ahead for some places. With a bit warmer nighttime temperatures in the forecast, you can safely plant or seed cool season vegetables outdoors such as cabbage family, peas, lettuce and other salad greens, potatoes, onions, carrots, beets, radishes. It is way too cool yet to sow beans or corn outdoors or to plant out starts of tomatoes, peppers, squash, cucumbers, basil and other warmth-loving plants. It has also been too cold in most places for those tender plants to spend the night in unheated greenhouses or tunnels, though the plants will be happy there during the day. They can stay out at night once night temperatures start staying mostly above 10oC (50oF). I am holding off on planting out celery and celeriac seedlings as these are readily vernalized by a spell of by a spell of 5-10oC weather (which can cause them go to seed prematurely, rather than produce a crop). The catch is that the bigger the plants, the more readily they go to seed in response to cool weather. More on vernalization in my Feb. 20, 2022 message.
Low temperatures are one problem, but the continuous wet weather is another, because the soil hasnât had time to dry out enough to handle. When soil is cultivated while wet it destroys soil structure and results in hard clods as the soil dries out. The worst damage comes from traditional âdigging overâ (turning the soil upside down with a shovel or fork) and especially from rototilling (we now know both practices are undesirable--see next paragraph). However, even minimal disturbance can cause some clods to form. This makes more work to break up clods to prepare seed beds, so try to wait until the soil is drier before handling it. Note: While the surface of seed beds should be reasonably level, there is no need for a fine textured surface. In fact, a rough surface helps to keep seeds from washing away during heavy rainfall. Large seeds can manage to send shoots up through a coarser layer of soil, but tinier seedlings canât push up clods. It works well to sow small seeds on the surface of a roughly prepared bed and then sprinkle a thin layer of finer soil over top of the seeds, just enough to cover them.
Cultivating soil? Minimizing soil disturbance benefits the complex community of microbes and other creatures that are most numerous in the upper 10 cm (4 inches) of soil and are vital for maintaining healthy, fertile soil. Once a year, when a bed is empty, I spread compost and any other amendments needed, on the surface. Then I use a garden fork to comb or lift and shake the upper 5-10 cm (2-4 inches) of soil enough to lightly mix amendments into the top layer of soil, but without turning the soil over or mixing thoroughly. Thatâs it for the year--after that I continue to plant and replant crops in quick succession in the same soil as spaces open up and crops mature, without further disturbance other than what occurs as I remove old plants and plant new ones. If you have heavy clay or compacted soil, then you may need to loosen the soil more deeply by pushing a garden or pitch fork into soil to the full depth of the tines and rocking it a little bit before removing it. The main things to avoid are turning the soil upside down, which buries the soil community where they wonât thrive, and pulverizing the soil, which impairs the soil structure, causes compaction and harms beneficial organisms in the soil.
When to move seedlings into larger pots? If you have tender seedlings you canât plant yet, they may have outgrown their containers. One indicator is seeing root tips poking out of the holes in the pot. If you gently slide the root ball out and see a network of roots surrounding the root ball, it is time to move it to the next size of container (choose a pot that is bigger by at least a finger-width all the way around the root ball). Most seedlings at garden centres have reached the maximum size for their containers by the time they are put out to sell, so if you bought plants, but couldnât plant them within a week, then they probably need to be moved into larger pots. Buying the youngest looking seedlings available, rather than the largest ones, gives you more time to hold plants before they suffer from being rootbound. Beware of buying veggie starts that have:
- grown leggy or floppy due to lack of sun (e.g., from sitting too long in the back of a rack of seedling shelves);
- burned or brown leaf tips (often caused by poor watering practices, although lately I have seen tender plants in grocery store racks that look like they might have been frosted);
- long âbeardsâ of roots trailing out of the pot;
- discoloured yellowish or orangish lower leaves, indicating they are severely stressed and suffering nutrient deficiencies.
There is plenty of time to start over from seed for plants of broccoli, cauliflower, cabbage, etc. if you now have seedlings in poor condition for whatever reason. Cool season vegetables, such as lettuce and salad greens can now be sown directly in the garden and is not too late to start seeds of squash, cucumbers and melons (indoors, though!). It is getting late to start over for tomatoes and peppers, but you should be able to find plenty of plants for sale if you need to replace starts that didnât work out.
Hail damage: With the frequent hail storms in the region over the last couple of weeks, veggies that were planted in the garden earlier in the month may now be showing hail injury. This looks like tiny white specks or dots in an all-over pattern on leaves of cabbage, broccoli, lettuce and other plants with wide, soft leaves. Unless plants were torn up by very large hailstones, they wonât be noticeably affected by the small marks where leaf cells were dinged by hail. Any new growth that didnât experience hail will be fine.
Hail damage.
Beware of birdies: Robins, juncos, towhees and others that look for seeds, worms, insects on the ground can be quite destructive as they pull up seedlings and eat seeds in the course of their searches. Quails are particularly notorious for pecking leaves and scratching up seed beds. This year birds have even been yanking out my newly planted onion sets. Protect plantings by laying wire mesh, chicken wire, bird netting or floating row cover flat over seed beds or on supports over seedlings. Or make self-supporting cages or cloches out of wire screening or wire mesh, tall enough to cover plants until they are about a foot high. Especially protect peas (birds really like those big seeds) until they well establishedâlast year I had netting over peas well into June before the birds finally left them alone.
Labelling plants: Several people inquired recently about systems for labelling plants, frustrated by lost tags and mix ups. I also find pot tags are a pain and often get lost (especially when my dog was a puppy and saw plant tags as toys or menu items...). I label individual pots, seedling flats or cells with masking tape using a waterproof ink pen. It is easy to put a piece of new tape over the old one when re-using pots next season or to pull off the tape label and stick it on a larger pot when I pot on seedlings. Once seedlings are permanently planted in the garden or greenhouse I draw their locations in on a sketch of the garden bed and label them on the drawing in my garden record book. Usually, the only time I put markers in garden beds is when I want to designate plants to keep for seedâand then I need tall, easy-to-see stakes or ribbons tied to the plants to remind me not to harvest them accidentally.
