As many gardeners know, there’s a common rule of thumb that advises when it’s OK to start planting flowers and vegetables:  You should hold off on planting until after Mother’s Day. Many people grew up hearing these words of advice from parents and grandparents who likely heard them from theirs. The guideline is an important reminder that early spring isn’t the best time to start planting most things, but is it a hard-and-fast rule that everyone should follow? Take a look at how much truth there is to the Mother’s Day guideline and how you can know when to start planting:

The Mother’s Day Rule: Is There Truth to It?

When it comes to deciding when to plant flowers, vegetables, shrubs or anything else, what matters most is your particular area’s last frost date. That’s because, depending on the hardiness of the plant, gardening when temperatures still reach the 20s overnight could mean setting your garden up to fail. So, how does the Mother’s Day rule fit into that? Well, in many climate zones, Mother’s Day signifies late spring, or when night and morning frosts are almost (if not completely) over for the year. However, the rule doesn’t take into account warmer climates or hardier plants, both of which can have different planting rules. There’s some truth to the Mother’s Day rule, but it’s best to take it for what it is: a general guideline.

Finding Your Last Frost Date

So how do you know exactly when to start planting flowers and vegetables? The best way to do this successfully is to find your area’s last frost date by doing a little research online. The National Climatic Center Website has frost information for all states, so it’s a good starting point. Then, you should research the exact plants you wish to put in your garden. Determine when to plant each one based on the frost information you found.

When to Plant Flowers

In general, annuals, perennials and bulbs all have different levels of hardiness. In other words, some grow well in cold weather and other hard-to-grow-in conditions while others need just the right amount of sunshine and warmth. The hardiest of flowers can be planted as soon as the soil in your garden can be worked, even if it’s several weeks before the last frost of the season. For half-hardy flowers, hold off until a couple weeks before the final frost, and for tender flowers, plant when there’s no chance of frost for the rest of the season.

When to Plant Vegetables

Like flowers, vegetables have different hardiness levels, and thrive in different circumstances. Cold-hardy vegetables, including spinach and onions, can be grown in cold early spring conditions, while others, like beets, carrots and potatoes, should be planted a little bit later. Wait until freezing temperatures have completely passed before you plant warm-weather veggies like squash, tomatoes, eggplant and basil.

Quick tip: If you’re starting from seeds, the seed packets for both flowers and vegetables will have instructions that tell you when to plant them based on your area’s climate and frost dates. If you’re starting with seedlings or are transplanting plants, look them up online first.

What to Do If the Cold Comes Back

If you’ve planted tender or warm-weather crops a bit too early, or you have unexpected cold fronts that brings freezes, there are steps you can take to protect your garden. If you’re expecting an overnight frost, cover your garden with a sheet or light blanket and then a layer of plastic to insulate the garden with warmer air. Remove the coverings first thing in the morning, as soon as the temperatures are back to normal.