Caroline Lewis is a Portland, Oregon, urban gardener whose company, Verdura Culinary Gardens, is dedicated to helping gardeners be more successful at raising their own organic vegetables. A licensed landscape contractor, Verdura installs raised bed gardens including trellises and drip irrigation systems, creates custom year-round planting plans, and offers vegetable garden coaching and maintenance programs. Caroline welcomes your comments and can be reached at caroline [at]

Preparing to plant

A garden checklist for March

March 5, 2012

Although it may still seem quite early, this is the time of year when we all need to get our gardens rolling: planning the plantings, building garden frames, ordering and starting seeds, cleaning up from winter, and amending soil.

Otherwise, we run the risk of missing out on the all-important early-spring season: peas, lettuce, spinach, arugula, onions and more. (And if you have never tasted home-grown peas, you’ll just have to trust me that this is well worth doing).

Remember that the key to growing vegetables year-round is planning — and to understanding that planting is not just something that takes place when the tomatoes go in the ground in May. Here are some tips on what to do this month.

Plan for the entire year

Successful gardens don’t get planted all at once. For example, let’s assume a summer garden is filled with tomatoes, onions, basil, Swiss chard, and carrots. They’re all growing at the same time, but the onions were likely planted in March, and the tomatoes and basil in May and June, respectively. These may have been preceded with peas or spinach in the same areas. The chard and carrots, on the other hand, may have been succession-planted any time from April through August.

Seed packs.

So it takes some big-picture thinking to plan a garden. The goal is to plant varietals that are well acclimated to your climate, at the right time, and spaced correctly, all with the goal of maximizing their health and productivity. Succession planting is a huge help in spreading out the harvest so you have a nice amount of any given vegetable — not too little and not too much — at any given time.

My favorite example of this is carrots. A lot of people just sprinkle an entire packet of carrot seeds on the ground in April with the intention of thinning them later. But a packet of carrots seeds (usually 1 gram) contains around 700 seeds! Even with aggressive thinning, that’s going to be way more carrots than one family can consume at one time. Why not plant a single square foot or two in early spring (carrots are perfectly spaced at 16 per square foot, or 3 inches apart) and then repeat every three or four weeks? And by making shallow indentations and just dropping a couple of seeds in each one, you’ll have enough carrot seeds in one packet for several years (which is great, because the usual seed life of carrots is exactly that).

Build your raised beds

Why raised beds? This is the only way we garden anymore, and with good reason. We don’t like back-breaking tilling and digging, and we definitely don’t like the ongoing battle with weeds and slugs. Well-made raised beds are an investment initially, but once they’re in, they’ll give you years of relatively carefree gardening. In addition to our own 10 raised beds, we have built hundreds for clients in the Portland area. We don’t own a tiller and rarely use more than a trowel, a spading fork, and a spoon as gardening tools.

Additionally, raised-bed gardens heat up more quickly in the spring, giving us a jumpstart on warm-season crops like cucumbers, squash, and tomatoes. If filled with a good soil blend, raised beds drain well and provide a perfect growing medium for your plants. We do not miss trying to grow in heavy clay soils!

Finally, raised beds planted with square-foot gardening methodology are incredibly productive. Check out this real-life example of the list of veggies we’ll be growing this year in just one of our client’s 4-foot-by-8-foot garden beds:

Brand-new raised beds look so inviting.

Bush beans (2 varieties)
Bush peas (2 varieties)
Carrots (3 varieties)
Lettuce (5 varieties)
Onions (3 varieties)
Peppers (3 varieties)
Radishes (4 varieties)
Tomatoes (3 varieties)
Vining peas

Note: Please do not build your new raised beds out of pressure-treated lumber, which can leach potentially dangerous chemicals. Cedar, Douglas fir, redwood, or juniper are all great choices.

Order your seeds and starts

As soon as you know what you’re planning to grow, get in your seed orders! With the explosive growth of home vegetable gardening over the past several years, seed companies tend to sell out quickly, particularly of the heirloom and organic varieties. Here is a listing of seed-company catalogs.

Locally, you can buy seeds as well as plant starts at a variety of locations, including nurseries, natural-food stores, and farmers’ markets. In the Portland area, our very favorite resources are Gales Meadow Farm at the Hillsdale Farmers Market for organic, heirloom plant starts and Naomi’s Organic Farm Supply for starts, seeds, soil amendments, chicks and ducklings, and much more. These are wonderful local businesses with superior products and freely shared knowledge — do consider shopping with them before you head to a big-box store!

Clean up your garden

If you already have a garden, I’m sure you did a wonderful job last fall removing those old tomato vines and cages and other assorted debris. Because you did, the slugs had no place to hide all winter in your garden beds. Even so, March is the perfect month to clean up those beds and get them ready for spring planting.

To do so, remove all plant debris, leaving only over-wintering onions, garlic, kale, and anything else you want to keep. If your beds have been strung to mark off the square feet, remove the string. If possible without damaging them, gently move drip lines out of the way. Now you’re ready to add spring amendments.

Amend your soil

One disadvantage of raised beds is that because they drain so well, nutrients tend to leach out over time. The beds should be amended in spring and, as needed, later in the season. We usually add lots of good compost and worm castings as well as some feather meal or other nitrogen-rich organic fertilizer and bone meal. We also like Naomi’s Mineral Mix, a balanced blend of trace nutrients.

Add whatever amendments you’re using, following package directions. (Note that there’s virtually no such thing as adding too much compost, so add enough to get your soil level where you want it.) Mix everything up, being careful to avoid the roots of established plants (we usually just sprinkle the mixture over these as a top-dressing). Then reposition your drip lines and restring the beds.

This is also a great time to repair trellis netting, if needed. Now you’re ready to plant!

Start planting

We try to plant all of our onions and peas before the end of March. Onions require as long a season as possible to fully mature. Because peas tolerate very chilly conditions, we can get them in and out in time to plant other warm-season crops later on. Other early-spring veggies to plant include spinach, arugula, any cold-tolerant salad greens, radishes, kale, collards, broccoli, beets, carrots, and turnips. Getting these into the ground soon — and then continuing to plant throughout the growing season — will help ensure you have your most productive garden yet.

There are 4 comments on this item
Add a comment
1. by Laura Parisi on Mar 5, 2012 at 2:26 PM PST

My garden needs some serious work. Question: Grass is starting to poke through in some of my raised beds. On one of the shorter ones, I removed the soil in the fall and lined the bottom with cardboard to stop the grass from popping through. But I have another bed that’s at least 2 feet deep and I can’t fathom removing all of the soil. Do you have any tips for stopping grass? It is so invasive!

2. by Storage Sheds on Mar 6, 2012 at 8:20 AM PST

Thanks for sharing a very informative post! I am into organic farming and your post definitely help me a lot.

3. by Caroline Lewis on Mar 6, 2012 at 10:03 AM PST

Hi Laura--

The best way to prevent this issue is to avoid having grass grow up against the sides of your raised beds. When we install raised bed frames, we remove all sod to a foot or so away from the edges of the beds, then put down landscape fabric and a pathway material, such as crushed gravel or bark mulch. If you were to do this now, you could probably dig out some of those obnoxious roots that have worked their way into your frames. It is extremely difficult to remove grass once it’s grown up into your beds, as you’ve learned. The cardboard trick won’t really help long term because cardboard will eventually break down, plus of course the grass will just work its way in around the edges of the cardboard if you allow the grass to grow right up against the edge of the frames.

Hope that helps, and happy gardening!


4. by Laura Parisi on Mar 6, 2012 at 10:53 AM PST

Thanks for the info, Caroline! Maybe if I put down landscape fabric around the walls of the bed, I can at least stop further invasion of grass. I have hazelnut shells on the pathway now but the grass grows right through them. There may be nothing I can do for the grass that’s already gotten in but at least I can stop more, right?

Add a comment

Think before you type

Culinate welcomes comments that are on-topic, clean, and courteous. For the benefit of the community we reserve the right to delete comments that contain advertising, personal attacks, profanity, or which are thinly disguised attempts to promote another website.

Please enter your comment

Format: Bare URLs are automatically linked; use this style: [ "place text to be linked here"] for prettier links. You may specify *bold* or _italic_ text. No HTML please.

Please identify yourself

Not a member? Sign up!

Please prove that you’re not a computer

Culinate 8

Kale in the raw

Eight versions of kale salad

Eight ways to spin everyone’s favorite salad.

Graze: Bites from the Site
First Person

The secret sharer

A father’s legacy

The Culinate Interview

Mollie Katzen

The vegetarian-cooking pioneer


Down South

Barbecue, tamales, cocktails, and more

Local Flavors

A winter romesco sauce

Good on everything

Editor’s Choice