May is moving day for young seedlings. I’m constantly moving trays of flowers and vegetables from the grow room to my pop-up greenhouse for more space, or I’m letting them harden off outside to get them ready to go in the ground. When they go out, they make room for the next crop of flowers and vegetables to sprout for midsummer. If you catch me outside, chances are I’ve got a few seed packets in my pocket to remind me to put something in the ground too. Summer is just beginning, but there are already a lot of seeds that need planting, either indoors to grow into seedlings or directly outside.
The Ultimate Beginner's Guide to STARTING Seeds Indoors
Take advantage of the last rains to germinate your grass seed. If your lawn has areas that need reseeding or you’re planning to create a full summer lawn, work with your local garden center to find the right seed. Germination really depends on water, so you’ll want to balance the last frost date and warm enough weather for the seed you’re planting with enough rain so you don’t have to water constantly.
It’s not just traditional lawns either. If you have an eco-lawn or clover lawn, you can fill in the area by adding red and strawberry clover seed for the summer, as well as English daisy seed. Ideally, you don’t create a monoculture of one type of seed, so other low-lying flowers can be added.
In most parts of the U.S., you’ll have enough sunlight this month to sow seeds directly outdoors, meaning you’ll plant them in the ground rather than trying to start seedlings indoors and transplant them outside later. If you’re direct-sowing annuals like wildflowers, you can plant them in the ground as soon as you’re reasonably past the risk of frost. Check the packaging for instructions on how deep to plant your seeds—many seeds won’t germinate if you just scatter them on the ground; they need a covering of soil. Your sunflower seeds, for example, need to be planted about an inch deep. A good rule of thumb is that seeds should be planted as deep as they’re large. So small seeds like celosia and poppy are fine to surface-sow, but marigolds and zinnias should be planted about a half-inch deep. If you want to spread the seeds to get a more natural look instead of poking holes for the seeds, scratch an area so that the seeds are in contact with the soil, then scatter them and cover them by sprinkling soil over them and pressing it down. Finish by watering.