Gardening with Allen: Plant wisely; frost still possible
By Allen Wilson
Published: April 17, 2020, 6:04am
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I would like to get my flowers and vegetables planted while I am off work. Is it safe to plant now?
The average last frost date in Vancouver is today, April 18. There is still a 50 percent chance of frost after that date. Higher elevations could have frost even later. Many vegetables and flowers will tolerate frosts down to 26 degrees, but most of the popular ones can be damaged by frost.
Because we have cool temperatures until well into May, I avoid planting the warm weather vegetables until next month. I have found that when planted outside, they tend to avoid growing until weather warms. Those planted outside a month later often pass up the earlier planted ones.
It is easy to remember which vegetables like cool weather. If you eat the roots, stems, leaves or flower buds (for example, broccoli and cauliflower), it is cold-tolerant. With the exception of peas, if you eat the fruit, it prefers warm weather.
The most popular cold-tolerant flowers include pansy, petunia, alyssum, snapdragon, carnation, dianthus, sweet pea, dusty miller, daisies and poppies.
I like to plant larger sizes of tomato and pepper plants in late May.
I often purchase 4-inch pots or smaller sizes in April and repot them into larger pots. I put these outside in the sun during the day and bring them inside at night. This combination of cool bright days and warm nights causes plants to have thick compact stems that develop into strong healthy plants outside.
Geraniums, impatiens, begonias and zinnias are warm weather flowers that have a slow start when planted before May. I have done the same inside-outside treatment with these plants. I start with 6-pack plants and transfer them to 4-inch pots. Another approach I have used is to plant them outside early and cover them temporarily with floating row cover. This is a spun fiber fabric that creates a greenhouse effect by trapping solar heat inside. You just lay the fabric over the plants with no support. Use soil around the edges to keep the wind from blowing it off.
You can use the same fabric over your tomatoes and other warm vegetables to protect from frost and speed growth when planting early.
Red plastic poly mulch is another way to speed growth of tomatoes, melons and other warm weather vegetables. After soil preparation, place the plastic and secure the edges with soil. Then make “X” holes for inserting the plants. Red plastic mulch not only speeds growth by warming the soil but also prevents weed growth.
Black poly can also be used but it is less effective at warming the soil and speeding plant growth than red plastic.
