Raise Your Garden Game
Michael Bartunek has built a few raised beds in his day, working his way up from an apprentice at a Milwaukee urban farm to Senior Farm Manager of the Ohio City Farm, one of the largest in North America. He generously shared his tricks of the trade at a Raised Bed workshop that we co-hosted. His approach to planning, building, sowing, and maintaining grow structures that are off the ground and contain soil and plants is well considered -- the extra touches pay off in the long run.
He breaks it all down in categories, starting with Planning. Where you put a raised bed depends on what you want to grow in it. If you're going for sun-loving plants like tomatoes and peppers, you need a spot in your yard that gets at least 6 hours of direct sun per day. If you're going for herbs, lettuces, and part-shade-tolerant plants, you can be a little more flexible. If you're not sure, snap a picture every hour of the day of where you want your raised bed to go to document whether or not 6 shots have full sun. When thinking about what plants go where, he has found that planting things in their own sections of the bed works better than mixing it up.
"If you're going for permaculture you can mix perennials and different annuals, but, if you're planning a section-by-section approach you could do perennials in one quadrant and, as they grow, they won't shade out annuals."
Next is Structure. You have a variety of border materials -- from fallen tree material to a rot-resistant cedar or hardwood (1 x 4") plank -- to choose from. He's even reused bricks, stacked and glued together with construction adhesive (and lined with a garden fabric so the glue doesn't touch the soil).
The benefit to a raised bed structure is to preserve your investment in soil and plants from eroding away.
Once your basic structure is complete, you're ready to fill it with soil. If you're building over existing soil that has a loose structure, six inches deep is sufficient. If you're going over hard ground, plan on a 12-inch depth. Tilth's bedding mix Grow has the water-retention qualities and nutrient contents he prefers.
"Be picky on what you choose for soil. You’re going to be putting a substantial investment into the ground. If you look at total investment, spend more on the soil then the structure."
Once your structure and soil are in, you have the option of making a trellis. Certain veggies, such as peas, love growing up a trellis. Place stakes in vertically and wrap the space between them using a thick, water-resistant line. He uses masonry line (the kind that brick and stone masons use to snap chalk lines).
A word about preserving your wood frame and stakes: his favorite preservative is Eco Wood Treatment (it’s a powder mixed with water and sprayed on with a pump bottle).
"It creates a patina finish and protects especially cheaper wood, like pine."
Maintenance is all about coverage: keep your beds covered with leaves or mulch at all times to keep wind and rain from leaching nutrients away.
His plant Protection game is next level. He builds deer fencing from six-foot-tall 1"x 1" wooden stakes driven into the ground and wrapped with metal "chicken wire." Or, he fashions protective coverings to keep hungry critters like rabbits out of the garden -- tenting it with flexible pipe material and covering it in thin mesh sheets (there is a flexible chicken wire that is easier to work with). Shorter fencing similar to the deer fence works -- the key is to make it as easy for you to get in as it is to keep pests out. He also drapes netting over berry bushes to keep birds from feasting on precious fruit.
"Everything is going to want to eat your garden. Ask your neighbors who garden what they have been dealing with” — from deer to groundhogs. It will save you finding out the hard way.
When it comes to Water, he does it by hand, until that routine gets old, then he recommends a sprinkler with an inexpensive automatic timer. Some are connected and can be scheduled or turned on via Bluetooth. Aim for a total of 1-inch of rain per week.
During the Q&A, he talked about what to plant before the final frost -- peas, radishes, cabbages and lettuces don't mind the colder nights. They'll keep you busy until it's time for heat-loving plants like cucumbers to be transplanted from a window sill inside to outdoors. He talked about bringing your indoor starts outside to acclimate to cooler temperatures and wind (His pro tip is to place a low fan on his seedlings when they're growing indoors to build up root strength -- as part of the hardening off process to the outdoors). He also talked about overwintering crops like onions and garlic to get a jump on things.
As for bed prep, he recommends a soil (pH) test to know if added nutrients or soil is needed to bring balance. He likes to cut plants down to the ground in the fall, but keep roots in place to continue feeding the soil and hold it in place. He's even been known to plant a cover crop like winter rye for extra nutrient exchange and protection from the elements (just turn it under with a spade when the season changes to spring.).
Follow these tips and, with a little practice and perseverance, you'll be gardening with the best of them.