Interbay Mulch

When you put your garden to bed for the winter, that doesn't mean nothing happens during the dark, cold, or snowy months. Left bare and exposed to the elements, important nutrients will wash away, and soil organisms will go dormant or even freeze to death.

There are many ways to over-winter your garden while at the same time improving the soil for a head start next spring. One way to invest in your beds was invented at Seattle's Interbay P-Patch: Interbay Mulch.

While similar to sheet composting or Lasagna gardening, Interbay Mulch attempts to bring critters responsible for decomposition all the way to the top layer of organic matter. The full distribution of organisms makes this composting method somewhat faster than sheet composting.

Making Your Mulch

Once your beds are cleared of this season's crops, create a mix of equal parts greens (grass clippings, coffee grounds, fresh chopped plants, composted manure) and browns (fall leaves, non-pressure treated sawdust, dry plant material, etc.) just like you would for a hot compost pile. Though it's tempting to use mostly browns, thinking there's plenty of time for them to break down, be sure you add enough greens for a balanced decomposition process.

Spread your mix in a good foot-thick layer (or more if you have the stamina) on your planting beds. Water the mixture well to wet it down, then cover it all with a layer or two of burlap bags. Wet down the burlap too (or soak the bags in water before placing them). The burlap keeps the mulch dark, damp and insulated so organisms can work all the way to the top of your batch.

That's all there is to it! During the winter, check your mulch every few weeks to be sure it's still slightly damp. You might also turn your mulch at least once during the winter.

Room and Board

Gardeners have experienced a few problems with Interbay Mulch. During the chilly winter months, mice or rats sometimes set up house in the mulch as it retains a bit of warmth under the burlap blankets. If you've incorporated kitchen scraps into the mulch, rodents may not even have to go far for food! You can minimize this problem by excluding food waste from your mulch, and checking under the burlap for rodents every few weeks.

Moist burlap also provides the kind of environment slugs just love! During your occasional winter bed checks, pick out any slugs and kill them.

After a few years of experience, several gardeners at Interbay have noticed that too much organic material can cause their beds to shed water in the dry months. Interbay Mulch may not be appropriate to use every winter. Next winter, plant a cover crop where you had mulch this year. Then rotate back to mulch the year after that.

In the Spring

By the time spring rolls around, your Interbay Mulch will be finished. A few weeks before you're ready to start planting, remove the burlap and turn the beautifully decomposed mulch into the soil. You'll notice a better response from your vegetables and flowers next year as your investment this winter pays off!

More Reading

Here are two great articles about Interbay Mulch on the web. Read them for a more detailed history and additional recipes.

Interbay Mulch at GardenWeb

How to bake a batch of compost at The Christian Science Monitor

Copyright © 2003 Brian Ballard. All rights reserved.

Build a Simple Coldframe

Spring never comes soon enough, and summer never lasts long enough! One way to extend our growing season is to use a coldframe to trap heat and shield plants from chilly winds. This lets you grow crops later into the fall, and start planting earlier in the spring.

To build a simple coldframe, you will need four six-foot cedar fence boards, about five feet of pine or cedar 2x2, 32 two-inch nails, a section of clear or translucent plastic slightly larger than three-feet by three-feet, a hammer, and a regular office stapler or staple gun.

Cut each fence board into equal three-foot halves (or ask the home store or lumber yard where you buy the boards cut them for you). Cut four 10½-inch lengths of the 2x2 with a hand saw.

The fence boards will become the walls of your coldframe. The 2x2 sections will provide a nailing surface for the ends of the fence boards. Nail the ends of two fence boards to two 2x2 sections. Stand these wall sections up, and nail two of each of the remaining fence boards to each end to form a square as shown in the photo below.











Once you have the walls of your coldframe all attached, spread the plastic across the top and staple it all around the edges of the coldframe. You may want to insert cross-brace or two just under the plastic to support it in rainy weather. I've used old sticks or bamboo for cross-braces.

Your coldframe is now ready to use. Place it over low-growing leaf crops in the fall. Place potted seeds under the coldframe to sprout, or leave it over seedlings or transplants until they're well established in the spring. On those rare sunny or warm days, you may need to prop up one edge of the coldframe with a brick so your crops don't bake. Once you're done with the coldframe, discard the plastic and break the frame down into flat sections for storage until the next time you need it.

Copyright © 2005 Brian Ballard. All rights reserved.

Dealing With Garden Debris

Every autumn, you begin harvesting bumper crops of vegetables! With that harvest, you'll have lots of extra plant material to get rid of. Here are some helpful tips on what you can do with your green debris.

The best way to get rid of your extra plant material is to chop it and return it to the soil, either by burying it directly in your garden beds or by starting a compost bin. You can also lay the chopped material between rows of plants, or dry it in your paths.

Some plant leaves can simply be shredded by hand. Stems and vines can be cut up with a pair of small clippers. Larger items or heavy stems can be chopped. Machetes, sugar cane knives, cleavers, and hedge clippers work fine for chopping. Find the tool that works best for you. Use a scrap of old lumber as a chopping block.

If you have a large volume of debris, why not start a compost pile? Mix your chopped green material with fall leaves that are plentiful around harvest time. You might also donate your chopped greens to a fellow gardener who is making a compost pile.

Copyright © 2003 Brian Ballard. All rights reserved.

Save Browns for Spring Composting

Just as Seattle gets too much water in winter and not enough in summer, compost materials can be difficult to balance across the seasons. Spring brings us too many "greens" while fall brings us too many "browns" for a balanced compost pile. The solution is to save some browns now to use next year's compost. Unlike "greens" which tend to get stinky if you try to store them, browns will patiently wait until you're ready for them.

When autumn leaves start falling, offer to rake your neighbor's lawn, or collect leaves from local side streets. Get your kids or grandkids into the act! Collecting leaves will be less messy if you get a head start on the rains, but even wet leaves will store fairly well.

If you have an out of the way location that won't be unsightly, store your leaves in plastic garbage bags. If not, simply pile the leaves on your garden plot after harvest time. Cover the pile with burlap weighted down with stones to keep your leaves from blowing away. You could even build a wire cage at your plot to store more leaves.

Some P-Patches make arrangements with the city to deliver leaves cleared from public streets or parks. If your P-Patch has enough room to store lots of extra leaves, contact the P-Patch office about setting up delivery.

When spring finally rolls around, mix your saved leaves with fresh grass clippings, coffee grounds, and other "greens" to start a batch of compost. If you keep the leaves a year or more, they'll eventually break down into great "leaf mold" that you can use to start seedlings or to mulch your garden. Don't let the word "mold" scare you – that's just the term for old leaves that have broken down to the consistency of soil.

Copyright © 2004 Brian Ballard. All rights reserved.