What to plant this week in Fairbanks, AK
Fairbanks gardeners are in a critical transition phase as the long winter retreat officially ends with an average last frost date of May 15. While many heat-loving crops like Zinnias and French Marigolds are listed for harvest, you must wait until mid-May to plant them outdoors safely given the -40°F lows that define our Zone 3a climate. Focus this week on harvesting your early maturing crops like Bush Beans and Carrots while preparing cold frames for any remaining late sowings.
The next 7 days
Fairbanks, AKGrowing in Fairbanks right now
- Do not attempt to transplant anything yet; our permafrost influence and short growing season mean only garlic can be planted now, requiring a strong start before the brief summer heat arrives.
- Protect your harvesting Zinnias and Sunflowers from sudden temperature drops by using row covers at night if a spring chill forecast is issued after May 15.
- Beefsteak Tomatoes are ready to harvest, but be careful not to damage the vines as they are still hardening off for the remaining frost-free days until September 15.
- Rutabagas and Winter Squash listed for harvest need immediate picking and curing to withstand our long sub-zero winters before storage.
Sow this week
1 crops- Garlic
Transplant this week
Nothing is due to go out this week.
Harvest soon
29 crops- Beefsteak Tomato
- Borage
- Brussels Sprouts
- Bush Bean
- Carrot
- Cleome (Spider Flower)
- Cosmos
- Dahlia
- French Marigold
- Garden Geranium (Zonal)
- Garden Verbena
- Garlic
- Lantana
- Leek
- Ornamental Sweet Potato Vine
- Parsnip
- Petunia
- Pole Bean
- Potato
- Rutabaga
- Scarlet Runner Bean
- Shiso (Japanese Basil)
- Summer Savory
- Sunflower
- Vinca (Madagascar Periwinkle)
- Winter Squash
- Yellow Summer Squash
- Zinnia
- Zucchini
Seasonal tips
- Finish succession planting cool-season greens like lettuce or spinach to maximize the short growing window before frost.
- Apply a thick layer of mulch around winter squash and rutabagas to protect roots from dropping temperatures.
- Prune back any leggy borage or cosmos stems to encourage fresh growth for late summer flowers.
Pest & disease watch
- Watch for early aphid colonies on the newly emerging leaves of your Pole Beans and Scarlet Runner Beans as temperatures stabilize above freezing.
- Monitor for cutworms attacking young seedlings if you are planning indoor starts that will move outside next week, as they thrive in our moist spring soil.
- Check Borage and Shiso plants for leaf miners which can become active quickly once the soil warms up past May 10.
Watering this week
Water deeply in the morning to reduce evaporation, but avoid wetting foliage to prevent fungal diseases on tomatoes and squash.
Harvest zucchini and summer squash frequently when they are young to encourage the plant to keep producing fruit throughout the season.
Fairbanks gardening questions
3Can I start my tomatoes indoors now to get a head start?
Yes, you should start Beefsteak Tomato seeds indoors immediately; however, do not transplant them outside until after May 15 when the frost danger has passed.
What is the best way to store the Winter Squash I am harvesting this week?
Harvest your Winter Squash and let it cure in a warm, dry spot for two weeks before moving them to a cool (40-50°F), humid location like an unheated garage.
Are the Garlic listed as 'sow now' planted underground or on top of the soil?
Plant your Garlic cloves with the pointed end up and about 2 inches deep in well-drained soil, ensuring you get them established before our first frost of September 15.
Other cities in zone 3a
1See the full zone 3a guide → · Plan your Fairbanks garden in SproutGuide →