Protecting brassicas from cabbage worms

If you are growing cabbage, Brussels sprouts, broccoli, cauliflower, kale, radish, turnip, or rutabaga, you may need to take steps to protect your plants from cabbage worms.  These green caterpillars love to chow down on brassicas and similar plants; after they pupate, they emerge as small, cream-coloured moths (that have a couple of dark spots on their wings).

There are many natural ways to control them, such as attracting their predators into your garden.  One simple solution is to construct a cover made of tulle (a fabric commonly used to make prom dresses and the like).  This fabric mesh allows in rain and sunlight but prevents moths from entering and laying their eggs.

You don’t need to make anything fancy.  You can make a wire hoop frame, or simply set up some stakes that you can drape the fabric over so it does not sit on the plants (as I have done above, on my hail-damaged plants).  Place something heavy on the edges of the fabric, where they rests on the ground.  Or, you can construct something permanent.  There are plenty of ideas on the internet.

For more information on cabbage worms, and other methods of controlling them, see https://www.planetnatural.com/pest-problem-solver/garden-pests/cabbageworm-control/.

Direct sowing cool season crops

Once the snow has melted, and the soil is workable (that is, it is neither frozen, cold, or very wet), you may direct sow cool season crops.  These plants tolerate overnight temperatures that hover around the freezing mark, and even a touch of frost; they prefer the cool temperatures of spring and fall rather than the heat of summer, during which they may bolt (go to seed too quickly).

Refer to the seed package to see how many weeks prior to the last frost that you may sow the seeds.  The package may also list an ideal soil temperature.  You may choose to place row covers over the area that you are planting to expedite the warming of the soil and protect your plants from occasional cold nights.

The following plants are quite hardy, and can tolerate a soil temperature of around 5°C:

  • Leeks
  • Peas
  • Radishes
  • Spinach, lettuce, collard greens, kale, kohlrabi, and other greens
  • Sunflowers
  • Turnip and rutabaga

The following plants are also quite hardy, though they prefer a slightly warmer soil temperature of around 10°C:

  • Broccoli (shown above), Brussels sprouts, cauliflower, and cabbage
  • Beets
  • Carrots
  • Chard
  • Kohlrabi
  • Onion sets
  • Potatoes
  • Parsnips

Growing vegetables in hot, dry conditions

Following are some tips on how to encourage a productive garden during a hot, dry summer:

  • Choose varieties that mature quickly and produce smaller fruit.
  • Lay your garden out so that plants that need similar amounts of water are grouped together.  Raised beds retain more water than open beds.
  • Plant in groupings or hexagonal offset patterns rather than rows so that the leaves can provide shade.  Space plants 1.5 to 2 times further apart than usually recommended to provide plants with access to a larger area from which to draw moisture.
  • Sow tall plants, such as corn and tomatoes, on the south side of heat-intolerant plants such as leafy greens, to provide them with shade and lower the temperature.
  • Add large amounts of organic compost to the soil; this helps trap moisture and encourages deep roots.
  • Apply a thick layer of mulch to the soil to prevent moisture loss and keep the soil cooler.  This will also help prevent the growth of weeds, which compete with your plants for water.  You can use natural materials such as grass clippings, straw, dried leaves, pine needles, or shredded bark.
  • Water plants heavily when they are very young, and producing blossoms or fruit.  During other times, they can do with less water. Use drip hoses, which direct water into the soil, rather than spraying the plants from overhead where it is wasted on the leaves.  Water in late evening and early morning.
  • You can place shade cloth over the south sides of eggplant, pepper, and tomato plants.  This will reduce the temperature by 5-15 degrees and may prevent sunscald.  Plants like peppers and eggplants may produce less during a drought, but they will still produce.

Avoid planting these vegetables

Vegetables like peas, brassicas (cabbage, broccoli, etc.), and leafy greens like cold weather, so they won’t do well in the heat of summer.  You can try planting them in the early spring or late fall, when the heat is less extreme.

Do try these drought-tolerant vegetables

  • Amaranth
  • Artichokes – Jerusalem and globe
  • Arugula
  • Asparagus
  • Beans
  • Chard
  • Chickpeas (I made the mistake of overwatering these and they started to germinate in the shell!)
  • Chinese cabbage
  • Cowpeas
  • Cucumbers
  • Eggplant
  • Endive
  • Garlic
  • Leeks
  • Melons
  • Mustard greens
  • Okra
  • Onions
  • Oregano
  • Peppers
  • Rhubarb
  • Rosemary
  • Sage
  • Savory
  • Squash
  • Sweet corn
  • Sweet potatoes
  • Thyme
  • Tomatoes
  • Watermelon, especially the sugar baby variety

The great zupumpkin!

In one of my first small gardens, I planted a pumpkin plant and a zucchini plant next to each other.  I didn’t save any of their seeds, but the next year, when I spotted a pumpkin plant coming up from the compost, I let it grow.  It started out looking like a bit like an elongated pumpkin or some sort of squash.  Then it ripened to the above specimen, which was christened the zupumpkin.

Cross-pollination

Cross-pollination occurs when an insect or the wind carries pollen from one variety of plant to another.  The resulting seed, when planted, sprouts a hybrid of its parents.  Since zucchini and pumpkins are both varieties of the same species, they can create the zupumkin (or zumption or pumcchini–your choice) but a cucumber and squash can’t procreate because they’re different species.

Cross-pollination does not affect the current year’s crop, but rather the next year–with one exception: corn.  If the pollen from the tassels of one variety of corn are blown into the silks from another variety, the cob that develops is a hybrid.

Self-pollinating plants

Vegetables like beans, peas, peanuts, eggplant, peppers, lettuce, and tomatoes are self-pollinating. Their seeds will produce plants like the parent, but insects will occasionally cross them, so if you want to be absolutely certain that your seeds will grow true to type, plant each variety at least 10 feet apart.

Insect- and wind-pollinated plants

Vegetables that are pollinated by insects or wind need to be separated by variety, and grown a distance apart (the distance varies with each type of plant).   To ensure that your seeds grow true to type, grow one variety of each type, or separate the different varieties.

Vegetables that willingly cross-breed

The following plants or plant families are prone to cross-pollination.  If you are planting them with the intention of keeping their seeds, keep varieties well separated.

  • Beets and Swiss chard
  • Cauliflower, cabbage, kale, Brussels sprouts, kale, collard greens, and broccoli
  • Corn
  • Cucumbers
  • Honeydew, cantaloupe, and other melons, excluding watermelons
  • Peppers (hot and sweet)
  • Squash (some varieties)
  • Zucchini and pumpkins