What to plant this week in Whitehorse, YT
Whitehorse gardeners are in the final sprint as the average last frost date hits May 15, requiring you to act fast on your late spring harvests. This week marks a critical window to pull up Bulbs and root crops like Garlic and Leeks before the inevitable September 15 first frost locks the ground down.
The next 7 days
Whitehorse, YTGrowing in Whitehorse right now
- The Yukon's short growing season means your Harvest Soon list items like Pumpkins and Winter Squash must be gathered immediately to avoid freeze damage.
- Soil in Whitehorse remains cold-wet into late spring; wait for dry spells before transplanting any late-blooming flowers from your harvestable list.
- High altitude UV intensity is already peaking, so apply mulch heavily around potatoes and parsnips to retain moisture and regulate soil temperature fluctuations.
Sow this week
1 crops- Garlic
Transplant this week
Nothing is due to go out this week.
Harvest soon
15 crops- Beefsteak Tomato
- Brussels Sprouts
- Bush Bean
- Cosmos
- Dahlia
- Garden Verbena
- Garlic
- Leek
- Lisianthus (Prairie Gentian)
- Ornamental Sweet Potato Vine
- Parsnip
- Potato
- Pumpkin
- Sunflower
- Winter Squash
Seasonal tips
- Finish hardening off any indoor starts before the ground warms up next month.
- Prepare raised beds now by adding compost to improve drainage in heavy clay soils.
- Order spring bulbs and seedlings early since local nurseries will be out of stock soon.
Pest & disease watch
- Late-season aphid swarms on Sunflowers and Cosmos as temperatures climb above 50°F in early May.
- Root maggots are actively targeting your newly planted Parsnips and Potatoes before the summer heat sets in.
- Powdery mildew can develop quickly on Dahlia leaves if humidity is high during this cool, wet transition period.
Watering this week
Clean and sanitize your pruning shears now so they are ready for spring deadheading and shaping next month.
Whitehorse gardening questions
3Can I still start transplants now that we are near May 15?
With an average last frost of May 15, it is risky to transplant tender crops unless you have hardy varieties ready for immediate outdoor exposure. Focus your energy this week on harvesting your 'Harvest Soon' list like Beefsteak Tomatoes and Brussels Sprouts instead.
My Garlic was marked as sowable now; does that mean I plant it in the ground or pots?
Since Garlic is listed under 'sow_now', you should plant cloves directly into the soil now to establish roots before winter dormancy. Do not delay, as planting after mid-May significantly reduces bulb size and yield for next summer.
How do I protect my Winter Squash from the coming frost?
Pick your Winter Squash immediately this week while they are still hard-skinned and fully mature on the vine. Leave them to cure in a warm, dry shed away from direct moisture until you store them for winter.
Other cities in zone 3a
1See the full zone 3a guide → · Plan your Whitehorse garden in SproutGuide →