What to plant this week in Edmonton, AB
Edmonton gardeners are currently navigating the tail end of a late frost period, with the average last frost date falling on May 12. While the mercury has warmed enough to harvest early summer crops like bush beans and cucumber, keep an eye out for any lingering cold snaps before moving tender plants outdoors. This week marks the transition from waiting out the freeze to actively harvesting your warm-season staples.
The next 7 days
Edmonton, ABGrowing in Edmonton right now
- Protect young garlic cloves planted this week with row covers if a sudden dip below -10°C occurs overnight, as Edmonton's spring volatility is notorious.
- The clay-heavy soil common in the Northlands benefits from adding organic matter now; harvest weeds like clover to chop-and-drop into beds before they set seed.
- With rainfall often concentrated in brief summer thunderstorms, check drainage on raised beds where potatoes and squash are growing to prevent root rot during heavy downpours.
- Plan your late-summer succession planting immediately after harvesting bush beans or cucumbers to maximize the short window before the September 25 frost date.
Sow this week
1 crops- Garlic
Transplant this week
Nothing is due to go out this week.
Harvest soon
45 crops- Basil
- Bell Pepper
- Borage
- Brussels Sprouts
- Bush Bean
- Cantaloupe
- Celery
- Cleome (Spider Flower)
- Cosmos
- Cowpea (Black-Eyed Pea)
- Cucumber
- Dahlia
- Edamame
- Fennel
- Flour Corn
- French Marigold
- Garden Verbena
- Garlic
- Ghost Pepper (Bhut Jolokia)
- Gourd (Ornamental/Bottle)
- Habanero Pepper
- Honeydew Melon
- Leek
- Lima Bean
- Lisianthus (Prairie Gentian)
- Loofah (Luffa)
- Nasturtium
- Ornamental Sweet Potato Vine
- Parsnip
- Pole Bean
- Potato
- Pumpkin
- Scarlet Runner Bean
- Shiso (Japanese Basil)
- Summer Savory
- Sunflower
- Sweet Corn
- Thai Basil
- Tomatillo
- Vinca (Madagascar Periwinkle)
- Watermelon
- Winter Squash
- Yellow Summer Squash
- Zinnia
- Zucchini
Seasonal tips
- Start planning succession planting schedules so that when your zucchini and squash are done, you can replant in their spots immediately.
- Prepare cold frames or row covers now to protect any tender seedlings from unexpected early frosts before May 12.
- Organize your transplanting tools and labels for the upcoming wave of peppers, beans, and melons that will be ready to move outdoors.
Pest & disease watch
- Watch for aphids clustering on new growth of basil, zinnia, and sunflowers as temperatures stabilize above 60°F.
- Monitor squash and pumpkin vines for powdery mildew, which thrives in the humid pockets created by Edmonton's frequent afternoon storms.
- Check tomato cages and pepper plants for early signs of stink bugs, a common local pest that targets bell peppers and tomatillos this time of year.
Watering this week
Water deeply in the morning to encourage deep root growth, especially for thirsty crops like cucumbers and pumpkins.
Garlic planted now will need consistent moisture during its establishment phase, so keep the soil evenly moist but not soggy.
Edmonton gardening questions
3Can I transplant basil or tomatoes now even though it hasn't been 100% frost-free?
Yes, but only if the soil is workable; wait for a clear forecast with highs consistently above 65°F to avoid shock on your transplants. If a chill is predicted within 48 hours, move sensitive seedlings under temporary row covers until it passes.
Is it safe to plant garlic in Edmonton this week given the zone 4a climate?
Absolutely; planting hardy garlic varieties now gives them enough time to establish roots before the deep freeze returns. Mulch heavily with straw after placement to insulate the bulbs against our harsh winter lows.
My zucchini plants are already producing, but I'm worried about end-of-season squash bugs.
Inspect the undersides of leaves daily and hand-pick any eggs or young nymphs you find before they hatch. Applying a thin layer of diatomaceous earth around the base can also deter crawling adults from reaching your harvest.
Other cities in zone 4a
2See the full zone 4a guide → · Plan your Edmonton garden in SproutGuide →