Winter Vegetable Gardening on the Coast

There are those of us who just can't give up the taste of fresh produce from the garden.  Nevermind the December storms, pouring rain, gale-force winds... we have to get our fix.

By now nearly all of my outside raised beds in the garden have been put to rest with cover crop and a blanket of straw.  Perennial herbs and pathways are newly dressed with wood-chip mulch, and tender hanging baskets have been brought inside.  Still, there are opportunities for winter vegetables with a little extra effort.

The enchanted Swiss chard forest in December

Normally this time of year I would still have large kale plants, which after frost come into their glory with sweetness.  Unfortunately this year the kale patch had to be rotated at just the wrong time due to poor planning and I didn't manage to get the winter crop started on time.  Other brassicas fared better, with my broccoli and cauliflower just finishing a few weeks ago (late November).

A star of the garden this past year has been 'Bright Lights' chard, with another bumper crop this year, and quite a few of the volunteer seedlings carefully transplanted to the front and side yards for use in the "edible landscape."  If you want to add edibles to your manicured front yard, this selection is outstanding for color, structure and it holds throughout the year.  When it finally bolts to seed there is a spectacular tall (over 5') spike that rises and produces thousands of seeds... so cut that and lay it down where you want a new patch.

Garlic has been planted for next season, and the herbs all neatly trimmed with a final harvest in late fall going to the drying shed.  There are still a few late artichokes on my established plants, and the foliage adds a striking evergreen texture to the front yard landscape.

The tomato house - center lid left in place

Access to the tomato house via end panel

Finally I wanted to share some options for off-season cold frames.  Nearly every ambitious vegetable gardener will know already about season-extension by the use of these adaptable little structures, merely a rectangular frame with some sort of removable glazing for the top. They are useful in starting early or keeping late many marginal crops like baby lettuces or Asian greens, and critical for transitioning plants that were started inside in the spring.

Small cold frame by peach tree - doing temporary duty storing straw

We have identified a few sunny spots in our tight city landscape where we custom-built frames from reclaimed materials, and another is used in the garden for growing tomatoes.  You will note from the pictures the variety of design, depending on how it's used.

Gull-wing cold frame - designed to fit SW facing nook

Important on the coast is to provide a way to secure the lid for high winds.  The last thing you want is an airborne lid crashing through your neighbor's window... or some other tragedy.  Also be sure to create a sloped lid on your frame, so that more light enters from the south.  Remember the sun is at a very low angle at our 45-degrees-north latitude in winter; a box with equal sides will create too much shade inside for your plants.  If you create a very tall frame like our tomato-house, be sure there is access on the sides for planting, harvesting, etc.  It will be impossible to manage just from the top.

Detail of lid construction - note angled top edge

Additional resources - great books I use on this topic include Winter Gardening in the Maritime Northwest and Gardening Under Cover: A Northwest Guide to Solar Greenhouses, Cold Frames, and Cloches

Water Runs Downhill

We are challenged by water on the central coast of Oregon.

In the summer, at the height of our growing season, it can be downright scarce. At that time of year, it's plain that the lack of planning for adequate water-- given our wind and sandy soil-- is to blame for many gardening failures.

But in January... oh yes and November, December, February, March etc... it's the opposite. We receive some of the highest rainfall counts in Oregon, 70-90 inches. Cascade Head, only 10 miles north of Lincoln City where I live, receives around 100 inches per year. By comparison, Portland receives merely 37-40 inches. Gives you some idea of what is considered "normal rainfall" on the central coast.

So what happens to all that water? Certainly the vast majority ends up in our rivers, streams and eventually the ocean. But it has to get there first... which gets me to the point of this post's title. Many homeowners here just don't plan for where the deluge is going to go, and what damage or benefit it may leave in its path.

One of the most obvious and lasting effects is on our soil. High rainfall totals equal acidic soils. Did you ever wonder why our soils west of the Cascades are "acid" and those east of the mountains are "alkaline" or less acidic? The falling rain leaches minerals like calcium and magnesium. In order to make our soils more palatable to the widest array of plants therefore may require annual applications of lime to boost the pH level. This is generally recommended for vegetables and lawns, and many other herbaceous plants.

The soil is likewise compacted by the constant falling rain, if it's exposed throughout winter. Protecting unplanted areas with mulches (bark, compost, straw) will make a huge difference come springtime. If the area is to be planted in spring/summer, simply pull back the mulch and compost it. In areas that you don't want lawn or shrubs, consider planting groundcovers in place of the annual chore of mulching. Many are low-maintenance and will thrive without extra water in summer. See my earlier post for some recommended spring-blooming groundcovers.

Drainage is no joking matter here. Take a good look at the slope of your property, locate your downspouts and storm drains. Now, where is the water going? Newer homes may have connected the downspouts to a storm sewer connection, but we have seen many that just drain out next to the house, across your treasured plant's roots, washing away bark and soil. The bigger the roof, the more water diverted, and the more potential damage. If you are not handy, consider asking a landscape contractor to look at whether you need French drains or other means to handle runoff.

When planning areas of hardscape (walkways, driveways) homeowners should consider permeable surfaces instead of concrete or blacktop. Selecting concrete pavers on a gravel foundation for your driveway, or even just using gravel as the drive surface, can help to keep vast amounts of water out of our storm sewers and improve groundwater by slower filtering as it moves through layers of rock and soil.

A personal pet-peeve of mine is bark on top of weedcloth, on steep slopes. The first time it rains hard, here comes your 3 inches of barkdust rolling down into the driveway, leaving ugly swathes of uncovered plastic fabric. Yuck. Again, this is a situation for groundcovers. Plant a dense selection and enjoy the view as they fill in; the added benefit is in preventing soil erosion from your steep slope. Plant roots hold soil in place better than anything else.

Obviously this is a big topic, and I am just scratching the surface. Let this be a gentle reminder to plan for rainy winter storms when you have the chance in summer. Happy New Year!

An update: OSU SeaGrant has posted a terrific resource guide for planning/planting "rain gardens." This could provide a beautiful and lasting solution to many homeowners' runoff problems.