Your questions, answered: How to get a head start on your gardening in St. Louis’ early spring

With early March temperatures already in the 60s and 70s, it is time to think about dragging out those pruning shears, pots and gathering mulch. It is spring gardening season! “St. Louis on the Air” gathered two horticulture experts to discuss spring planting and gardening.

June Hutson, a horticulturist, consultant and designer for the Kemper Center for Home Gardening at the Missouri Botanical Garden and Chip Tynan, the garden’s manager of the horticulture answer service, joined Don Marsh to answer your questions.

Spring is definitely here early this year. Tynan said he’s been calculating average “growing degree” days and as of yesterday, the number of them, 46, places St. Louis at about the 12^th of April in an average year. “We’re running about four weeks ahead of the season at this point,” he said.

Here is a selection of your questions, answered:

With the early spring, what should people be doing right now?

“With the temperatures we’ve achieved and the predicted 10 day forecast, we aren’t going to have a choice. Our plants will leave us in the lurch if we’re not out in the garden doing something. Removing leaf cover that might be on lawns, for instance. Probably wouldn’t be a bad idea to leave mulches in place around normal plants. When we have these kinds of warm-ups, could either be a boon or a bust.” – Chip Tynan

What is the best time of year to prune? What should we know about pruning?

Credit Kelly Moffitt | St. Louis Public Radio

“[Spring] is a good time of year to prune for some plants. If you’re looking at a plant you want to bloom in spring, you do not want to prune now. … For plants that bloom in the summer time, now is the perfect time.” – Chip Tynan

“Do as little as possible to start with, you can’t glue branches back on a tree.” –Chip Tynan

“It is kind of like hair.” – June Hutson

“Number one, it removes dead wood. There’s a certain amount of aesthetic shaping that goes into pruning. For the most part, a lot of people think you have to prune. But, you don’t. Let the plant become the plant that it wants to be, that it is genetically programmed to be. Think removal of dead wood as a primary reason and beyond that, proceed cautiously.” – Chip Tynan

How do you best grow sweet potatoes in a container?

“Whatever the container is, I would recommend a minimum of 12 inches, preferably 18 inches, deep. Make the container larger than you think you need. Regardless of what the material is (I’m a traditionalist, I would use a clay pot) make sure the container you use has drainage holes.” – Chip Tynan

“For one sweet potato, you need an 18 inch in diameter pot.” – June Hutson

Can you recommend a list of shrubs that are lovely and deer-resistant?

For problems with any kind of invasive species, Tynan recommends a trip to the Missouri Botanical Garden’s “Common Garden Pests and Problems” website. There, you’ll find a list of shrubs and other plants that don’t appeal to deer and, also, plants that particularly call to different kinds of animals. 

Can you recommend a variety of sweet potato that provides a better leaf for eating than others?

“To eat the leaves? Gosh. Well, locally, you don’t find a whole lot of variety of sweet potatoes. Vardaman is a standard that everybody carries. Beauregard is another. Most of the organic farms, that’s what you’re going to find. Eating wise? I’m going to eat a sweet potato leaf this year, I’ve never heard of that!” – June Hutson

“Do not eat tomato or potato leaves,” says Tynan. Sweet potatoes should be palatable because that type of potato comes from a different family than your typical baked potato.

What’s your advice on indoor herb gardens?

“Yes, lights. Think about how many grey days we’ve had this winter and herbs love sun, so you’re at a compromised climate for the winter growing of herbs. You need to put them in the sunniest window. The only sure way to grow herbs indoors in the winter would be artificial lights.” – June Hutson

Where can I find a local source of native wildflower seed mixes?

Credit Kelly Moffitt | St. Louis Public Radio

• Missouri Wildflowers (in Jefferson City)
• OK Hatchery (Kirkwood)
• Visitor’s Center at the Shaw Nature Reserve

“The wildflower mixes aren’t all alike. What you want to buy is one that says upfront it is for the Midwest because if you don’t get the particular one, you’ll get a burst a bloom in the first year and then after that it is all downhill because they aren’t the right species for our area.” – June Hutson

How do I divide Hostas and Monkey Grass?

“Hostas will be coming up really soon if it stays fairly warm. When you see their noses come up, dig up the whole clump and divide it with a shovel. You need a few noses on each piece. You could even wait longer into the season. Hostas are very forgiving. It is harder to get in there when they are fully developed.

“As far as Monkey Grass, Liriopi, we’ve already cut some back. It is a logistic thing for us because we have so much. Starting now, but pull it apart and make sure you don’t see new growth coming up in the clumps.” – June Hutson

What basic tools should a first-time gardener have?

• A digging fork.
• A spade or a shovel, a good sharp one.
• A nifty hand trowel. I love these little Japanese digging knives, we call them Hori-Horis. It is everything. It is a root pruning tool and trowel all-in-one.
• A rake. A garden rake and a leaf rake.
• A sharp hoe.
• Hand pruners.
• A good pair of gloves

– Chip Tyson

Last thoughts?

Credit Kelly Moffitt | St. Louis Public Radio

“Get on out there. Get your hands dirty. The secret to a green thumb is brown knees.” – Chip Tyson

Listen to the full interview here:

St. Louis on the Air brings you the stories of St. Louis and the people who live, work and create in our region. St. Louis on the Air host Don Marsh and producers Mary Edwards, Alex Heuer and Kelly Moffitt give you the information you need to make informed decisions and stay in touch with our diverse and vibrant St. Louis region.