March is bringing us a characteristic tilt of the see-saw that this month always brings. Tank tops can go back in the drawer for a little while, as this week we will see night-time temperatures dipping into the mid-20s. We are expecting rain (~1.6 inches in Boulder, ~3 inches in Denver!), and heavy, wet snow, too. We’ve been here before; no need to panic. And we need the moisture!
This is when it’s important to make sure your seed furrows are level (so the seeds don’t all wash down to the low end), and when row cover fabric comes to the rescue.
Credit: CSU Extension
Seed Guard, our lighter-weight row cover, can be laid directly over seeded areas to help keep seeds in place. Our heavier weight Ensulate can be stretched over support hoops to protect seedlings from being crushed by snow, while trapping valuable warmth emanating from the earth. Make sure your supports are less than 2 feet apart, or an accumulation of heavy wet snow could tear the fabric. In any application of row cover fabric, be sure to secure the edges well. I prefer to use spare lengths of 2×4 lumber or metal pipe to hold it down, but bricks and stones work, too.
Straw makes a good mulch for vegetable gardens, and if you apply it correctly, it can serve as protection from snow and heavy rain early in the season, when seeds have not yet germinated or when seedlings are small. Use straw straight from the bale, and pull it off in ‘flakes’. A flake is a layer gently peeled off from the end of the bale so that the stems remain knitted together. I aim for a rectangular flake about 1 inch thick. Lay the flakes on the soil so they overlap a little. Water it all down, unless rain or snow is imminent. The flakes will be easy to move to make room for planting starts and uncovering seed furrows. There doesn’t seem to be any ‘clean’ (seed-free) straw in Colorado. But when straw (or even hay) is handled this way, a minimum of grain seeds are released onto the soil. If you just tear the straw apart, you’re likely to have a lot of unwanted grain and some weeds growing in your garden.
If you’re wondering about the timing for sowing vegetable seeds, both indoors and outdoors, check out the Resources section on our website. Under Handouts/Vegetable Resources you’ll find lots of great resources, including the Boulder Culinary Gardeners (BCG) Planting Calendar: Front Range Planting Guide for Foothills and Plains.
While you’re in our Resources section, this would also be a good time to look at our instructions for pruning different types of Clematis and when to cut back the various categories of ornamental grasses.
Established perennials that are emerging in your garden should be just fine through this storm. If you’re worried about early daffodil stems and buds, cover the clumps with inverted pots until the snowfall has ended. Keep an eye on evergreen shrubs like Daphne, Boxwood, Scotchbroom, Curlleaf Mountain Mahogany, Fernbush and Manzanita, and gently brush or shake off heavy accumulations of snow so that their branches won’t tear or break.
ONIONS
Onion Starts
Our onion plants are here, both in bundles and in pots, and they can wait to be planted until you have a chance to prepare your garden. The bundled, bare-root plants should be kept cool and dry. Don’t be tempted to water or mist them! They will grow from their roots for up to 4 weeks. Our pots of organic onion starts can also be kept in their pots for a few weeks until you’re ready to transplant, and these should be watered when the potting soil dries out.
Here’s another tip, gleaned from farmer and author Elliot Coleman, for growing the best onions: Avoid planting onions where Brassica crops were grown the previous year (broccoli, cabbage, cauliflower, kale, collards, arugula, rutabaga, turnip, radish, rapini, mustard, pak choi). I have made this mistake myself, and found that in spite of doing everything else right (providing rich soil, generous spacing, full sun, no weed competition), the onions I planted where I’d recently grown broccoli were puny and disappointing.