Now that you know a bit more about Square Foot Gardening (SFG), let’s end this three-part series on the topic of planting.
It’s certainly not too late to start planting in Michigan. In fact, depending where you are, you might not have been able to plant any warm weather crops until this month. One handy map is the interactive USDA Hardiness Zone Map where you can enter your zip code and find out which zone you are in. This helps you determine what you can plant at any time of the year. For example – I live in Macomb, Mich. so I enter my zip code of “48044” and the map determines that I live in zone “6a.” Now I can use this information to find out which month of the growing season is appropriate for my seeds or transplants to be planted.
Another useful tool is finding your “last frost date.” At Dave’s Garden you can enter your zip code and find out which date is your predicted last frost date. If you’re planting warm weather crops like tomatoes, peppers, eggplant, and basil, you want to make sure you put them out when the possibility of a frost is gone. For Macomb, Mich. this date was May 15, 2015, but it varies all over Michigan and the United States.
Beds assembled? Filled with Mel’s Mix? Grids in place? Trellis up? If you answered “yes” to all of those, then you’re ready to plant! Let’s cover the basics of planting and how SFG is different from traditional row gardening.
Seed or Transplant?
I made a planting chart (see below or download a PDF) that will hopefully come in handy for some of you. It’s by no means inclusive of all the different types of plants you can put in your SFG, but it’s a good start.
For most plants you can buy seeds, transplants, or both. For most gardeners, it’s a personal choice, but transplants can be expensive and most plants have time to grow from seed. I know that those transplants are tempting! They give you the visual satisfaction that your garden is actually growing something. Interestingly enough, I compared the time it takes for plants to harvest from seed vs. transplant. By the time you can plant your transplant, your seeds will have already sprouted to the same size as the transplant. Furthermore, it’s cheaper to grow from seed.
OK, back to the planting chart. I indicated which option is best by shadowing that option in “pea” green (sorry, I couldn’t help myself!). Some plants like tomatoes, peppers and eggplants will need to be transplants because they don’t have enough time to grow to maturity from seed outdoors. You could start the transplants indoors, but you would need to this in the late winter/early spring months, such as February and March. Just be sure to “harden off” your plants before putting them out in your garden and out in the elements. “Hardening off” is a process by which you slowly get your new transplants used to being outside. You can learn more about it here.
Some plants including asparagus, potatoes, garlic and bulb onions come as “sets”, “tubers”, or “seed potatoes”. Asparagus is a perennial crop that will come back every year, but won’t produce for two to four years. This vegetable will also spread and produce more shoots year after year. Potatoes will come as “seed potatoes” from the store, or you can start your own from potatoes at home. Just remember, potatoes require 12” of soil so unless your SFG box is resting on top of your existing soil, you will need to make a top hat so that the potatoes have room to grow.
How Many Per Square?
You can reference the large chart above to determine how many seeds or plants per square. If the plant you’re planting isn’t listed, you can determine spacing based on what the back of the seed packet says. And wouldn’t you know … I made a guide for that as well (see below or download a PDF)!
The only exceptions to the spacing rule on the back of seed packets are for melons, cucumbers and pumpkins . Since these vegetables grow on vines they need lots of space. Even though you are using a trellis for these plants, the leaves need lots of space for airflow, which is essential for disease prevention. So be sure to follow the “two per square rule for cucumbers” and the “one per two squares” for melons, pumpkins, and squash.
Each seed has an optimal planting depth. There’s no need to bring a ruler out with you when planting, just estimate the depth using your finger. A good rule of thumb (or finger in this case) is to remember that the first knuckle of your index finger is 1 inch. The second knuckle is 2 inches. The third is 3 inches. Anything less than an inch can be estimated with a poke in the soil. If you have your children or grandchildren helping you (which you should, because gardening is fun for all ages), you’ll need to adjust for their fingers (e.g., the second knuckle on my kids is 1 inch).
Make sure you loosen up the soil with your hands or trowel before making the holes. Once you have the soil lose and the holes made, you can put in your seeds. I recommend having one “seed hand” and one “hole making hand”. When you come across the teeny tiny seeds like carrots and lettuce, they will stick to your fingers if they have dirt on them. When you have 16 holes to fill with tiny lettuce seeds, you can imagine your patience (and seeds) going out the window!
Please also keep in mind that one seed will give you one plant. This is one reason why SFGs are much more efficient than traditional row gardens. You don’t need to sow an entire row of seeds, and then come back to thin out the seedlings. Another benefit of SFG is that you are saving money by planting one seed! A package of lettuce seeds contains thousands of seeds. That’s thousands of lettuce plants for $1! What a deal! For the easy to manage large to small seeds, you only need to plant one. I plant two just in case one doesn’t germinate. For the tiny seeds, a small pinch (usually about three or five seeds) will do.
Once your seeds are placed in their new homes, loosely cover them with soil. Don’t pack it down. You want small amounts of light and water to be able to make it down and you want the new seedling to be able to emerge easily.
The last thing you need to do is water your newly planted seeds and/or transplants. Make sure you water the seeds consistently for two weeks. When watering transplants and your new seedlings, be sure to water at the base of the plant.
Maintaining Your Beds After Planting
The most painful part of SFGing is pinching off or cutting the extra seedlings that sprout. In most cases all the seeds that you placed in one hole will germinate and you will have several seedlings where only one should be. I’ve experienced this countless times. I head outside to see my beautiful little seedlings coming up to say “hello”, only to realize that now I must make the hardest decision of the growing season — which one gets to live and which one must die.
I know it sounds silly, but you wait until it happens. You may try to bargain with yourself and think, “Maybe I can transplant this little guy somewhere else?” or “Let’s just see what happens if I let him grow.” No, don’t do it. You must either take your small scissors and clip the extra seedling at the base, or pinch it off with your fingers. It’s for the best, as your other seedling will need to grow big and strong and turn into a high yielding, bountiful plant.
Other maintenance besides watering will be keeping an eye on any little weeds that grow from seeds being blown in. Weeds will be easy to find because you will know that you didn’t plant something in that spot, or simply because it doesn’t look like the other plants. Since the Mel’s mix is so loose, the weeds will come right out.
As I mentioned in my prior post, there’s no need for fertilizing, but you can if you choose. It can be in the form of top dressing with compost, or adding bone meal, blood meal, etc. For example I like to spray my pepper plants with Epsom salt solution because it gives them a little extra nutrients that they need. It’s not necessary, but I’ve learned little tricks to give certain plants that extra boost.
Most plants will continue to produce as long as you keep picking their fruit. Indeterminate tomatoes are good for trellising because they will grow as tall as you let them and they will keep bearing fruit. Some plants, like peas, will continue to grow and flower but stop when the weather gets too warm. There is no need to wait for lettuce to grow into a giant head. You can harvest the outside leaves and the plant will continue to grow. Our lettuce gets about waist high before it gets too hot and bolts (“bolt” refers to when the plant goes to seed and is no longer edible.) Some greens like kale continue to grow all year, even in the winter, as long as you harvest the outside leaves and let the inside grow. Broccoli is another great example. Once you cut off the main head, the stem will bear new florets that you can harvest throughout the year.
Some other gardening resources:
- Farmer’s Almanac: Best Planting Dates for Detroit
- MSU Extension Center: Gardening in Michigan
- Square Foot Gardening Foundation
I hope I inspired many of you to try square foot gardening. Always keep in mind gardening is a learning process that we obtain through trial and error. I’ve had an amazing garden that seemed to produce endless amounts of produce and I’ve had years where my entire garden failed. You will constantly be learning. You’ll also become a Google-certified entomologist from all the research you will do to determine which insects are eating your plants. Have fun with it! And remember there are communities of people who are either first timers or experts in SFG, so don’t hesitate to reach out to others for help. Thank you so much for your interest.
Good luck and happy gardening!
– Joohi Castelvetere is a nutrition and food science major at Wayne State University, a mother of three amazing children, and a certified Square Foot Gardening instructor. She’s also a Parenting Program volunteer.