Gardening in March
Posted on Friday, March 14, 2025 · Leave a Comment
Whether March came in like the proverbial lion or lamb for you, March is the time when you need to pay more attention to your houseplants. Instead of watering every Sunday, you probably need to water most things twice a week – except for cacti and a few plants that thrive in dry soil. But rosemary? It’s so easy to kill now. The sun is hotter, roots are growing, and they need more water. Don’t keep the soil soggy, but poke your fingers into the soil more often and make sure it’s not Arizona arid. A dry rosemary is a dead rosemary.
Don’t leave stubs, they have to heal back to branch collar
Although March is the time farmers tend to prune their fruit trees, I am waiting a bit. We still have too much snow to easily move around carrying ladders. Pruning experts will tell you that you can prune fruit trees any month of the year, something I have found to be true. But let’s go over a few rules for pruning.
Use sharp tools. A good pair of hand pruners, some loppers and a pruning saw are all you need. I don’t like bow saws – they can’t get into tight places. Know where to cut. Don’t cut branches flush with the trunk or a big branch. Each branch has a “collar” that should be left. This is the bulge where it heals. But don’t leave long stubs when you remove a branch. They will not heal properly, and look awful. Remove dead branches first.
Never remove more than about a quarter of the leaf-producing branches. Leaves are the engine that drive growth and flower and fruit production. Remove water sprouts each year or two. These start as pencil thin shoots growing straight up, but will get big and clutter up the interior of the tree. Remove branches that are rubbing or crossing others, or are growing in towards the center of the tree. Remember: sunlight should be able to reach every leaf. Open up the interior so this is possible.
Homemade A frame plant stand for starting seedlings
March is also the time I start planting seeds indoors. Onion family seeds and peppers, hot and sweet, can be started now. Artichokes and cardoon I start early, but tomatoes I don’t start until around April 10. That will give them 8 weeks to be ready to go outside in mid-June.
Actually, it is much easier to order onions as bareroot plants sold in bunches of 50, each a few inches long and ready to start growing in the ground in May. Johnny’s Select Seeds and others sell them, and your local nursery may sell onions in 6-packs, each cell with 4 to 6 seedlings. The main advantage to starting onions or tomatoes by seed is that you get a much wider choice in what you grow.
If you want to start plants indoors, you will need some lights. Yes, some people try a sunny window, but they generally get lanky plants leaning toward the sunshine. Kits with LED or fluorescent lights are sold at garden centers and online. I built my own, a simple A-frame wooden structure that has two plywood shelves and supports 4-foot lights. It can accommodate up to 12 flats of seedlings if I put some on the floor.
Metal planting cells from Gardeners Supply
Next you need 6-packs of either plastic (like the ones you get when you buy veggies or annuals at the nursery) or re-usable metal or heavy duty plastic ones. In my efforts to reduce my use of single-use plastic, I have switched over to re-usable plant cells. Yes, they are more expensive, but they last forever. In any case, get bigger cells, not smaller ones. Your babies are going to grow in them for 8 weeks or more and need plenty of room for roots.
You can buy seed starting mix, but if you do a lot of plants (as I do), it can get expensive. So you can mix the potting mix with good quality compost if you have it, or you can buy it. Seed starting mixes don’t have much nutrition in them, so adding compost helps. Or later, you can water with a dilute solution of liquid fertilizer, something like Neptune’s Harvest Liquid Fish and Seaweed Fertilizer.
You may wish to buy electric heat mats designed to provide consistent low-level warmth. This signals the seeds that spring is here, and gets them to sprout sooner and with better germination rates. Again, expensive, but they last forever.
Lastly, you can’t let your seeds/seedlings dry out. One way to prevent that is to buy clear plastic covers that fit over a flat of seedlings. Oh, and don’t forget to buy trays to hold your 6-packs. This keeps water from getting on to your table or floor.
Lastly, in March I am reading gardening books and magazines and planning out what I want to do in my flower gardens. I recently got a preview copy of a wonderful book by my friend Jill Nooney called “Bedrock: The Making of a Public Garden”. Jill and her husband Bob Munger have working on their property to develop beautiful spaces to try all sorts of plants. They bought the house in 1980 and have been working on them ever since. They turned over most of the land, gardens and Jill’s sculpture to a non-profit to own and manage last year, but they continue to live in the old farmhouse there and work in the gardens.
Why read this book? It is relevant to anyone who wants to develop great gardens. Jill is a plant collector who has tried just about anything that will grow in a Zone 4/5 garden, and the photos illustrate many of them. The color photos are numerous and beautiful. It is full of design ideas, too. And she has an engaging writing style. I loved the book.
Spring is just around the corner. Get busy now – it will help prevent the mud season blues!
Click Here to buy from Cobrahead