Missouri’s humid climate supports begonia planting in late April or early May, after frost danger ends. Knowing the best time to plant begonia in missouri is key to getting vibrant blooms all summer long. This guide covers everything you need for perfect timing and care.
Begonias love warm weather but hate frost. In Missouri, the last frost typically happens between mid-April and early May, depending on your zone. Planting too early risks damage; planting too late shortens the growing season.
Let’s break down the ideal window, step by step, so you can plant with confidence.
Best Time To Plant Begonia In Missouri
The best time to plant begonia in missouri is after the last spring frost, when soil temperatures reach at least 60°F (15°C). For most of the state, this falls between late April and mid-May. Check your local frost dates using the Missouri Extension Service map.
Here’s a quick zone-by-zone breakdown:
- Northern Missouri (Zones 5b-6a): Plant from May 1 to May 15. Frost risk is higher here.
- Central Missouri (Zones 6a-6b): Plant from April 25 to May 10. This includes Columbia and Jefferson City.
- Southern Missouri (Zones 6b-7a): Plant from April 20 to May 5. Springfield and Cape Girardeau warm up faster.
Always wait until nighttime temperatures stay above 50°F consistently. A cold snap can kill tender begonia transplants.
Why Timing Matters So Much
Begonias are tropical plants. They cannot handle frost at all. Even a light freeze turns leaves black and mushy. Planting too early means you risk losing your plants.
On the flip side, planting too late in June means less time for roots to establish before summer heat. Begonias need cool nights (60-70°F) to set buds. Late planting can reduce bloom time.
The sweet spot is when soil is warm but air temperatures are still mild. This gives begonias a head start before July’s scorching heat.
How To Check Soil Temperature
Don’t rely solely on the calendar. Use a soil thermometer for accuracy. Here’s how:
- Insert the thermometer 4 inches deep into the soil.
- Take readings in the morning and evening for three days.
- Average the readings. If the average is 60°F or above, it’s safe to plant.
If you don’t have a thermometer, watch for signs: dandelions blooming and oak leaves unfurling are natural indicators that soil is warming.
Choosing The Right Begonia Variety For Missouri
Not all begonias handle Missouri’s humidity and heat equally. Pick varieties that thrive in your region.
Wax Begonias (Semperflorens)
These are the most reliable for Missouri gardens. They tolerate full sun to part shade and bloom nonstop from May to October. They handle humidity well and resist powdery mildew.
Tuberous Begonias
These produce large, showy flowers but need more shade and consistent moisture. They struggle in direct afternoon sun. Plant them in containers or shaded beds.
Dragon Wing Begonias
A hybrid that loves heat and humidity. They grow tall (up to 2 feet) and produce cascading red or pink blooms. Perfect for hanging baskets in Missouri summers.
Rex Begonias
Grown for their colorful leaves, not flowers. They need indirect light and high humidity. Best as indoor plants or in sheltered outdoor spots.
For most Missouri gardens, wax begonias are the easiest choice. They handle the state’s unpredictable weather best.
Preparing Your Garden For Planting
Good preparation ensures your begonias thrive from day one. Follow these steps:
Step 1: Choose The Right Location
- Most begonias prefer morning sun and afternoon shade.
- Wax begonias can take full sun if watered regularly.
- Avoid low spots where water pools after rain.
Step 2: Amend The Soil
Begonias need well-draining, slightly acidic soil (pH 5.5-6.5). Missouri’s clay soil is often too heavy. Mix in compost or peat moss to improve drainage.
Test your soil pH with a home kit. If it’s too alkaline (above 7.0), add sulfur or pine bark mulch.
Step 3: Space Plants Properly
- Wax begonias: 6-12 inches apart.
- Tuberous begonias: 12-18 inches apart.
- Dragon wing begonias: 18-24 inches apart.
Overcrowding leads to poor air circulation and fungal diseases, common in Missouri’s humid summers.
Planting Begonias Step By Step
Once your soil is ready and the date is right, follow this process:
- Dig holes slightly larger than the root ball.
- Place the plant at the same depth it was in the pot.
- Backfill with soil and press gently to remove air pockets.
- Water thoroughly after planting.
- Add a 2-inch layer of mulch to retain moisture and keep roots cool.
For tuberous begonias, plant tubers with the concave side up, about 1 inch deep. Wait until sprouts appear before watering heavily.
Caring For Begonias After Planting
Missouri’s weather changes fast. Here’s how to keep begonias happy all season.
Watering
- Water deeply once a week, more often during dry spells.
- Water at the base to avoid wetting leaves, which causes fungal spots.
- Check soil moisture by sticking your finger 1 inch deep. If dry, water.
Fertilizing
Use a balanced liquid fertilizer (10-10-10) every two weeks during the growing season. Stop fertilizing in late August to let plants slow down before fall.
Deadheading
Remove spent flowers to encourage more blooms. For wax begonias, this isn’t necessary—they self-clean. For tuberous types, pinch off faded flowers regularly.
Pest And Disease Control
In Missouri, watch for:
- Powdery mildew: White coating on leaves. Improve air circulation and avoid overhead watering.
- Slugs and snails: Hand-pick at night or use iron phosphate bait.
- Aphids: Spray with insecticidal soap or a strong water stream.
Begonias are generally low-maintenance. Most issues come from overwatering or poor spacing.
Extending The Blooming Season
With proper care, begonias bloom from late spring until the first fall frost. In Missouri, that’s usually October. Here’s how to maximize bloom time:
- Fertilize regularly but don’t overdo nitrogen, which promotes leaves over flowers.
- Remove any yellowing leaves to keep plants tidy.
- If a heatwave hits, provide afternoon shade to prevent stress.
When fall temperatures drop below 50°F at night, bring container begonias indoors. For in-ground plants, you can dig up tubers and store them for next year.
How To Store Tuberous Begonias Over Winter
- After first frost, cut back stems to 2 inches.
- Dig up tubers carefully and shake off soil.
- Dry them in a warm, dark place for two weeks.
- Store in peat moss or paper bags at 45-55°F.
- Replant in spring after last frost.
Common Mistakes Missouri Gardeners Make
Avoid these pitfalls for healthier begonias:
- Planting too early: Even a late April cold snap can kill plants. Wait until May if unsure.
- Overwatering: Missouri’s humidity means soil dries slower. Let the top inch dry out between waterings.
- Ignoring soil pH: Alkaline soil causes yellow leaves and poor growth. Test and amend as needed.
- Planting in full shade: While begonias like shade, too little light reduces blooms. Aim for dappled sun or morning light.
Frequently Asked Questions
Can I plant begonias in Missouri in July?
It’s possible but not ideal. July heat stresses transplants. If you must plant in summer, choose wax begonias and water daily for the first two weeks. Provide afternoon shade.
What is the best time to plant begonia in missouri for containers?
Same as garden planting: late April to mid-May. Containers warm up faster, so you can plant a week earlier if you move them indoors during cold nights.
Do begonias come back every year in Missouri?
Only if you bring them indoors or store tubers. Begonias are not winter-hardy in Missouri. They are treated as annuals or overwintered indoors.
How deep should I plant begonia tubers?
Plant tubers 1 inch deep with the concave side up. Cover lightly with soil and water sparingly until sprouts appear.
Can I plant begonias under trees in Missouri?
Yes, but choose spots with dappled light, not deep shade. Tree roots compete for water, so water more frequently. Wax begonias work best under trees.
Final Tips For Success
Missouri’s climate is perfect for begonias if you time it right. Stick to the late April to mid-May window. Check your local frost dates every year, as they shift.
Start with healthy transplants from a local nursery. They’re acclimated to Missouri conditions. Avoid big-box store plants that may have been grown in greenhouses far away.
Mulch well to keep roots cool during July and August. Water consistently but don’t drown them. With these steps, your begonias will bloom from spring until the first fall frost.
Remember, the best time to plant begonia in missouri is when the soil is warm and the danger of frost has passed. Watch the weather, not just the calendar. A little patience in spring pays off with months of beautiful flowers.
If you have heavy clay soil, consider raised beds or containers. Begonias hate wet feet. Good drainage is non-negotiable.
Finally, enjoy the process. Begonias are forgiving plants. Even if you plant a week late, they’ll still reward you with color. Just avoid the extremes—too early or too late—and you’ll be fine.
Happy gardening in the Show-Me State. Your begonias will thank you.