ST. LOUIS — March 20 marks the official start of spring. This time of year, daffodils and crocuses begin sprouting.

However, gardening experts warn to hold-off until planting flowers in your garden.

Chip Tynan, a plant doctor at the Missouri Botanical Garden, recommends waiting until the beginning of May to plant. That’s typically when St. Louis sees its final frost of the season.

Tynan said gardeners can begin planting seeds in pot and planters now, but they have to be kept indoors until the weather warms up and the ground softens.

He recommends doing a simple soil test.

"If it breaks apart, loose into small particles, then it's just perfect. If you squeeze it and it stays a solid ball just wait a few days. Let it dry down a little bit,” said Tynan.

There are some plants that can be put into the ground now.

“Lettuces, cabbage, broccoli” said Tynan. Any time of European vegetables he said.

Now is also a great time to begin sewing grass seed.