GARDEN CAPSULE
The challenge: You’re confused about when to plant your vegetable garden. You see plants offered for sale, but you think the correct planting time is still weeks away.
The solution: April is the best month to plant seeds or transplants of all the cold-loving vegetables, including onions, peas, potatoes, lettuce, Swiss chard, radishes, broccoli, cabbage, carrots, beets, spinach and kale.
But don’t plant heat-loving transplants such as tomatoes, peppers, melons and sweet potatoes before mid- to late-May, unless you use season-extending devices such as a Wall o’ Water on each plant. The water-filled chambers retain heat and allow you to plant warm-season crops up to a month earlier than normal. You can also set pots of warm-loving crops in a cold frame until safe planting time, or practice the old but dependable method called hardening off: Put your plants in a cart or wagon and pull it outside when the weather is mild, then back inside before temperatures fall.
Pluses: An early start for the coldweather crops listed above produces a much more abundant harvest. With a season extender such as Wall o’ Water, you can be the first one on your block to harvest a vine-ripe tomato.
Minuses: Spring weather is fickle: keep an eye on the forecast. Temperatures below 50 degrees Fahrenheit can cause cold injury to heat-loving crops, even if spring lows never dip down to freezing. If you wait until planting time arrives to buy warm-weather transplants, the store may sell out of your favorites.
Sources: For a map showing average last frost dates in Wisconsin, go to plantmaps.com/interactive-wisconsin -last-frost-date-map.php. You can find Wall o’ Water, cold frames or other season-extending devices at most garden stores. You can also order by mail from Gardener’s Edge (888/5565676, gardenersedge.com) or Gardener’s Supply Co. (888/833-1412, gardeners.com).