Sorry folks! I hope you weren't too excited to see how to build a cold frame. I know I promised to post it this time but it's going to have to wait. Why? Because I read a book and was so inspired that I had to post this information instead. Not to worry though, I will be posting the how-to in Fall. I think we'll be able to get by with simple row covers till then!
Here in the Pacific Northwest our climate is temperate maritime. This means that our weather is moderated by our proximity to the Pacific Ocean, and specifically Puget Sound. These climates have a narrow range of temperatures without extremes which allows the opportunity to grow vegetables year-round, many with little winter protection. Take for instance the lowly brussel sprout shown below in early summer. The sprouts mature from the bottom leaves of the stock which is where you will harvest first. As the plant grows it produces more leaves which in turn produces more sprouts. As you harvest throughout the summer and fall the energy of the plant is concentrated into new production. Since the plant is cold hardy the fruit will continue to grow so you still have sprouts to harvest through the frost, sleet, and snow of winter with no protection for the plant. Snow cover will simply insulate the plant.
My final harvest of the season was the first week of February. The plants themselves took a beating but the sprouts were fantastic! The cold weather brought out the sweetness and because many were still young they were nice and tender. Some were the size of peas, others were the size of large marbles.
Sauteed in butter with a dash of sea salt and pepper brings out the sweetness. So delicious! Don't even try to compare these to what you get at the supermarket.
One sprout contains 37% of your daily vitamin K and 22% of your daily vitamin C (plus other good stuff!).
Many crops can be overwintered with simple row covers, mulches or cold frames. In this way cold hardy vegetables can be sown in late summer for harvest during winter months. By giving carrots, beets, parsnips, rutabagas and leeks a little mulch you'll harvest them all winter. With the large amount of winter rain we get in the PNW a good choice would be raised beds or containers placed in a sheltered position so root vegetables won't rot.
There are many leafy vegetables that will overwinter with a little protection as well. With these you'll want to use row covers, cold frames or cloches, keeping rain, frost, and wind at bay. Spinach, chard, arugula, cress and lettuces to name a few. Kale needs no protection and can grow right along side your brussel sprouts! Below are my cold hardy plantings for late winter plus overwintered rainbow chard. The row covers can warm the soil a full hardiness zone higher therefore coaxing the seeds into germination. Once germinated and the danger of frost past (about March 21st) the row covers can be removed.
This chart produced by Travis Saling will help you get started. http://westsidegardener.com/quick/winter_veggies.html
| Plant | Sowing date | Hardy to | Notes | ||
|---|---|---|---|---|---|
| Arugula | August 15-September 15 | 15F/-9C | Holds up reasonably well to rain | ||
| Beets | Best in July 1-10, will work if sown until the 20th | 20F/-7C | Can go colder with mulch | ||
| Broccoli | fall/winter | Anytime in June | 25F/-4C (?) | Rain will probably kill it before the frost does | |
| overwintered | July 15-August 1 | 10F/-12C | these are the biennial sprouting broccolis | ||
| Brussels Sprouts | May 15 | 0F/-16C | Seriously, these taste nothing like the store-bought ones | ||
| Cabbage (for winter) | June 1 | 5F/-14C (hardiest varieties) | I haven't grown the spring cabbages like First Early Market, so I really don't know the timing | ||
| Carrots | July 1-15th | 15F/-9C | With mulch, these can be depended on to overwinter. An August 1st sowing still give useable, but smaller, roots. With carrots there seems to be big differences that are just related to how particular varieties grow as the days get shorter. | ||
| Cauliflower | fall/winter | June 1-30 | 25F/-4C (?) | Rain and slugs tend to do mine in before the cold does | |
| overwintered | July 15-August 1 | 5F/-15C | Takes soggy soil somewhat better than sprouting broccoli | ||
| Chard | Up until early August | 20F/-7C | Even if the plant dies back, often the crown survives to regrow in the Spring | ||
| Claytonia/Miner's Lettuce | August 10-25 | At least 11F/-12C | Fast growing, compact, does well under cover | ||
| Corn Salad/Mache | August 20-September 1 | At least 8F/-13C | Seems to thrive unprotected in our rainy wet winters | ||
| Cress, Garden (Upland) | By late August | At least 15F/-9C | Biennial plants can be started as early as late spring | ||
| Escarole/Endive | August 1-10 | Reportedly 5F/-15C | Good cloche candidate, since wetness is more of a problem than cold. Bitterness decreases with frost, and varies from variety to variety. | ||
| Favas | September,October | 10F/-12C | I sow in late September. I've gotten away with sowing them in November; they will grow a little even in winter, during any spells when temps are above freezing! | ||
| Kale | July 1-15 | At least 8F/-13C | Needs no protection | ||
| Kohlrabi | July 10-20 | 15F/-9C | Can go lower with mulch or under cover | ||
| Garlic | September,October | At least 8F/-13C | I plant in late September. Basically, if the ground isn't frozen, you can put them in. | ||
| Leeks | April-Early May | At least 8F/-13C | Big differences between varieties in terms of hardiness and bolting date. This entry reflects my experiences with Durabel. | ||
| Lettuce | August 1-10 | 24F/-4C | Another good cloche candidate | ||
| Minutina | August 10-25 | ~ 15F/-10C | Unusual, almost succulent leaves | ||
| Mustard | July 15-August 10 | 15F/-9C | Hardiness is variable, depending on variety | ||
| Onions | Most types | August 10 | 0F/-18C | Most overwintered onions dry down in June. Waterlogged winter soils can be a problem for all overwintered onions | |
| Walla Walla sweet | September 1-15 | Reportedly -10F/-24C | Walla Wallas dry down in July. | ||
| Scallions | June-September | At least 10F/-12C | This applies to Allium cepa types of scallions. A. fistulosum types are much hardier and non-bulbing, but also are less tender and hotter in flavor. | ||
| Parsnip | June 15 - July 1 | At least 8F/-13C | It's fun trying to keep these seeds damp until they sprout! | ||
| Radicchio | July 15 | Reportedly 5F/-15C | Leaf types are easier and more reliable. Don't dawdle in sowing this one! | ||
| Radishes | Through September | Uncertain | Various rots and soil dwellers spoil mine by midwinter, even though the plants are still alive | ||
| Spinach | August 1-15 | At least 8F/-13C | Under a cloche they can be depended on to overwinter | ||
My peas, planted February 8th, are just starting to sprout under the row covers. The minimum soil temperature for germination is 40 degrees. That means the row cover has kept the soil temperature high enough to promote germination. Once peas are sprouted they can withstand frost so the row cover can be removed and a trellis put in place.
I was inspired by a book I just read by Eliot Coleman "Four-Season Harvest." Eliot and his wife live in Harborside, Maine where they tend a year-round organic farm. The book is laced with tidbits from their travels to France where they researched winter edibles. Maine lies on the same parallel as the south of France where winter vegetables have been harvested for centuries. The practice of winter harvesting goes beyond the tended vegetable garden into the fields and forests as foragers gather native winter edible greens. Here in the PNW these might include miners' lettuce, young dandelion, and fiddle head ferns. To get more specific, Seattle, Washington lies on the 47th parallel north which corresponds with Nantes, France at the outlet of the Loire river valley. It is famous for growing Muscadet grape. Because these areas have been inhabited for centuries longer that the United States there is much gardening wisdom to be learned by researching the local fare as Eliot and Barbara did.
My next post will begin a series on creating your own backyard apiary.
