What to plant this week in Helena, MT
Helena gardeners are in the final push for a successful 2024 season as we settle into stable growing conditions following our late May frost average. This week marks an ideal time to harvest your first crops of sweet corn, zucchini, and bush beans while enjoying the warm, dry air typical of our valley floor.
The next 7 days
Helena, MTGrowing in Helena right now
- Our valley soils in Helena can be heavy clay; this is the perfect week to amend beds with compost for summer crops like squash and tomatoes before they get too stressed by heat.
- With average last frost around May 12, cool-season giants like kale and collard greens are thriving now, but watch for bolting as temperatures consistently climb above 75°F.
- The dry summer pattern means you must water deeply in the mornings to combat rapid evaporation from our open terrain, especially for shallow-rooted crops like cilantro and lettuce.
- Take advantage of this week's warmth to finish any late sowings of snap beans or bush beans that might have been delayed by the early spring chill.
Sow this week
No direct sowing windows open this week.
Transplant this week
Nothing is due to go out this week.
Harvest soon
46 crops- Bachelor's Button (Cornflower)
- Basil
- Beet
- Bell Pepper
- Borage
- Bush Bean
- Cabbage
- Carrot
- Cauliflower
- Cherry Tomato
- Cleome (Spider Flower)
- Collard Greens
- Cosmos
- Cowpea (Black-Eyed Pea)
- Cucumber
- Dill
- Fava (Broad) Bean
- Fennel
- French Marigold
- Garlic
- German Chamomile
- Ground Cherry
- Kale
- Napa Cabbage
- Nasturtium
- Onion
- Ornamental Sweet Potato Vine
- Pansy
- Parsley
- Pole Bean
- Potato
- Rutabaga
- Scallion (Bunching Onion)
- Scarlet Runner Bean
- Shallot
- Shishito Pepper
- Snapdragon
- Summer Savory
- Sweet Corn
- Swiss Chard
- Thai Basil
- Tomato
- Vinca (Madagascar Periwinkle)
- Yellow Summer Squash
- Zinnia
- Zucchini
Seasonal tips
- Succession sow snap beans or Swiss chard every two weeks to ensure a continuous harvest through summer.
- Mulch around newly transplanted peppers and tomatoes with straw to retain soil moisture and keep roots cool as temperatures rise.
- Thin out carrot tops gently if they are overcrowded to allow the remaining plants to bulge up nicely for harvest.
- Stake tall crops like sweet corn, pole beans, and indeterminate tomato varieties now before heavy winds arrive.
Pest & disease watch
- Monitor for aphids on your newly transplanted tomatoes and peppers, which love the sticky residue left behind from our recent dry spells.
- Watch for cutworms attacking young carrot and cabbage seedlings, particularly in garden beds near the base of your fence lines.
- As heat builds, keep an eye out for spider mites on the undersides of zucchini leaves, which can spread quickly under Helena's hot, dry summer winds.
Watering this week
Water deeply at soil level in the morning to prevent fungal issues while ensuring thirsty crops like corn and beans get consistent moisture.
Pull weeds carefully around your garlic and onion beds now, as they are storing energy for bulb development before winter.
Helena gardening questions
3When is the best time to plant my garlic bulbs for next fall?
While you are currently harvesting garlic from your previous planting, it is actually too late to plant new cloves this week as our soil has already warmed up.
My cherry tomatoes and yellow summer squash are growing fast; how often should I water them?
Helena's dry summer air demands deep watering every two to three days, ensuring moisture reaches the root zone without wetting the foliage.
Can I still start basil from seed in Helena this week or should I only use transplants?
Since you are currently harvesting basil, it is best to take cuttings from your existing healthy plants rather than starting new seeds indoors.
Other cities in zone 4b
3See the full zone 4b guide → · Plan your Helena garden in SproutGuide →