Wondering what to plant in March?
The warmer weather and longer days in March are a great time to get your hands in the dirt! There are lots of seeds you can start this month.
The timing we write about below is geared for a growing zone 5 where the last frost is in mid-to-late May. Adjust timing accordingly if you have earlier or later frosts.
What vegetables to plant in March:
Sow Cool-Weather Veggie Seeds Indoors in March:
Start seeds for cool-weather crops like lettuce, cabbage, broccoli, and onions under lights indoors to get them ready to transplant outside next month in April. They will germinate and grow quickly under florescent or led grow lights, and can be transplanted after they've gotten a head start in the house.
However, you can sow many of these outside directly in the garden, too, read on...
Direct Sow these Cool Weather Veggie Seeds Outside in the Garden:
Spinach, cilantro, parsley, beets, carrots, snap peas, snow peas, lettuce, broccoli, cabbage – Cool weather veggies like these can be started outside. Keep the soil moist and they'll germinate when ready!
Note: Direct seeding Crops like Spinach, cilantro, parsley, beets,and carrots is best as they do not like to have their roots disturbed (unless they are transplanted soon after germination when they are still very small). It's also easier to direct seed them into the garden or container where they will be fully grown as there is no transplanting needed. Keep them moist and they will germinate when the conditions are right. 
Some cover helps keep the soil warmer to speed up germination, and grow plants more quickly:
While not required, it helps to have some cover like frost cloth, floating row covers, or simply an overturned clear plant saucer (see lower below) or other clear container such as the top of a vinegar jug or overturned clear storage bin. Make sure to vent and/or uncover on sunny days as it can get mighty hot under plastic! You don't want to steam the seeds or seedlings. Frost cloth and floating row covers breathe, so are better than plastic if you can't vent or open them as needed.
Many people grow cool weather veggies and herbs year-round in a small garden bed hoop house or a cold frame to keep the soil warmer during extra cold periods. 
A cold frame in the two photos above grows greens year-round, providing herbs and greens in January-March when nothing else is actively growing outside. As the days get longer, the plants take off for an extra early productive crop come April and May. 
Peas above growing in a small garden bed hoop house made of metal conduit with greenhouse film. These will take off over the next month!
In the photo above we used an old cracked clear plastic plant saucer to cover some spinach seeds to germinate them and keep them warm during super cold weather in March – it worked wonders and we had a large crop of spinach come April and May. Leaves can also help insulate cool-weather crops, and help feed the soil.
Carrots can sometimes be tricky to get to germinate.
Here's a trick for starting carrot seeds »
Starting Warm Weather Veggies Indoors in March:
In addition to starting lettuce, cabbage, broccoli, and onions indoors for transplanting outside in April, March is a great time to start pepper seeds indoors! Many people start their pepper seeds indoors in mid-to-late March – especially super hots as they take some time to get growing for spring transplanting. Pepper seeds germinate slower than most other vegetables, with some varieties taking 21+ days to germinate! So giving them more time than faster growing veggies such as tomatoes is best. We recommend starting peppers about 6-8 weeks before the last expected frost in your region. Make sure to pot them up if they start to outgrow their root space, and avoid having root-bound plants, which is one reason not to start too early if you don't have room to up-pot them.
Want peppers sooner this season?
You can also grow the fastest growing peppers which take off much faster than other varieties, and you'll be picking peppers sooner, and the plants will keep producing all season long.
Here's more of our pepper seed starting tips »
Other great warm weather vegetables and herbs to start in March include eggplants, basil, or Lavender. Basil is great to grow indoors in March and April as you can prune and use the leaves over pasta, on salads or sandwiches. Pruning it so it forms lots of branches will increase your harvest, and it grows happily under lights indoors through spring. We like to grow Basil in our Aerogarden all winter long as it looks so pretty and is useful in the kitchen.
Wait on Tomatoes... Until April:
We usually start tomatoes indoors about 4-6 weeks before the last expected frost (so later, in mid-to-late April), as they germinate and grow quickly so it's best not to start them too early unless you have room to pot them into much bigger containers as they grow. Tomatoes always outpace peppers so we typically start most of our peppers later in April vs. March.
What about starting zucchini, squash, pumpkins, and cucumbers indoors?
To be honest, there's really no reason to start zucchini, squashes, pumpkins or cucumbers early indoors. And especially not in March unless you are in a warmer growing region. Of course you can start them indoors, but they grow quickly so don't start them too early, they'll germinate and be ready to transplant in a matter of just 2-3 weeks – you'll want to transplant them just as after they get their first set of true leaves. You don't want them to get root-bound as these cucurbits don't like to have their roots disturbed. We recommend that you instead direct seed their seeds in mounds out in the garden around mid-May, or whenever the chance of frost has passed, they'll do just as well if not better than the indoor started plants, as they will quickly catch up and often outpace them!
One exception to this direct-seeding cucurbits advice, is that if you have a lot of pests like cutworms, which love to eat baby cucumber seedlings – especially in our garden – you may want to start them indoors away from pest pressure. We just usually succession sow several extra seeds in case a few get eaten, but you could also start them indoors a few weeks before so they get a nice thick stem and a first true leaf or two before transplanting outdoors.
So March is the time to get your gardening on! Planting seeds today will provide lots of hope and joy in the months to come.
Happy growing!
