Welcome to the first edition of The Hort Report, your weekly gardening guide tailored for Missoula area gardeners! As daylight stretches and our soil starts to warm, many become eager to get their hands in the dirt. But in Montana, knowing when to plant is just as important as what to plant. It is easy to get excited once the warm weather hits, but STOP, remember to years past..... did you get burned by Mother Nature? Even if days feel warm, a late frost can still zap your seedlings. Keep floating row covers or frost blankets handy just in case.
Understanding Frost Dates
Montana’s growing zones range widely, from USDA Zone 3 in colder mountain valleys to Zone 5 in milder river bottoms. The last expected frost date varies by location:
Missoula Valley: Around May 15–20 and High Elevation Communities: Often into early June
Soil Temperature = Go Time
Forget the calendar for a moment—your soil temperature is a more reliable planting guide. Use a soil thermometer (or meat thermometer!) inserted 2–4" deep into the soil:
- Peas, spinach, and radishes: 40–50°F
- Lettuce, carrots, beets: 50–55°F
- Beans, squash, cucumbers: 60–70°F
- Tomatoes, peppers, corn: 65°F+
Your soil warms faster on south-facing slopes and in raised beds—take advantage of those microclimates!
Hardening Off Seedlings
If you've started plants indoors, they need a week-long transition to outdoor life. Start with 1–2 hours in a protected spot, gradually increasing sun and wind exposure.
Checklist for Early May:
- Check your soil temperature and moisture
- Direct sow cold-loving veggies
- Begin hardening off indoor seedlings
- Clean and sharpen garden tools
- Mulch paths and prep beds
Remember, the key to gardening in Montana is patience and observation. Watch the weather, test your soil, and don't rush it—your plants will thank you! Check out our Pest Management Calendar online or stop by and pick one up. Keep up on all the pests showing up around Missoula @406-258-3820.
Sarah Holden is the MSU Missoula County Extension Horticulture Agent
Contact her at sarah.holden1@montana.edu or by phone 406-258-4205
