When to plant your veggies

Potted onions in the spring

Saturday, March 14, 2015

Wondering when to plant?  There are two key criteria for successful plant growth when it comes to the right time to plant-soil temperature and air temperature.  I have found some handy charts and tools to take the guesswork out of when to plant.

There are different ideal soil temps for different vegetables.  All seeds have to have a minimum soil temperature for them to sprout.  The closer to their ideal temperature, the higher the success rate for germination of the seed.  Here is a link to soil temperatures and germination rates:  Soil Temp Seed Starting

As your soil warms, your seedlings will grow faster.  One trick to use to give your seedlings a head start is to put down plastic before planting to preheat the soil.  If planting in a mulched bed, adding fresh mulch will also jump start your soil temps.

For air temperatures, knowing your first and last frost date in your area is key.  Cold season crops can be planted earlier than your last frost date whereas summer crops should not be planted until after your last frost date.  Here is a link for determining your last frost date:  Freeze-Frost Dates

Now that you know what your last frost date is, Johnny Seeds has a nifty chart you can use to calculate when to start your seeds and when to plant your seedlings and plants outside:  Seed Starting and Planting Guide

You don’t want to rush setting out your summer crops.  They really don’t like the cold weather and will shiver in colder temps and soil.  They are really good candidates for preheating the soil and using ground covers or a portable greenhouse to get a jump start on the season.

If you want continuous harvests of the same vegetable, there are two ways to accomplish this.  One is to buy the different types of the same vegetable with different “Days to Harvest.”  For instance, there are many kinds of broccoli and each matures at different times.  Some are ready to harvest in as little as 49 days while others can take up to 250 days.

Another option is to plant the same vegetable in your garden at staggered timing.  This is called succession planting.  Johnny Seeds has a handy spreadsheet for this, too.  Succession Planting Calculator

Pots heat up faster and cool down quicker than your garden beds.  You can use this to your advantage to give your veggies a head start.  Another great thing about pots are they are moveable.  In the spring, you can place them in full sun to warm the veggie.  Then, in the dog days of summer, you can move the pot to a shadier location.  This can help extend the harvest season of your cold season crops.