What to plant this week in Columbus, OH
With the average last frost date in Columbus hitting April 21, this week marks the critical window for transplanting your warm-weather crops before night temperatures dip toward that -5°F minimum. Gardeners are currently focused on harvesting early successions like bush beans and basil while preparing hardy perennials like dahlias and ornamental sweet potato vines for their outdoor move.
The next 7 days
Columbus, OHGrowing in Columbus right now
- Columbus clay-loam soils tend to retain moisture well but can become compacted; break up clumps around new transplants of zucchini and summer squash to ensure robust root establishment before the heavy spring rains arrive.
- Watch for late-season cold snaps that may linger past mid-May despite the calendar, making it wise to use row covers when protecting early plantings of garlic or leek against unexpected freezes near the Ohio River valley climate shifts.
- The region's tendency toward humid summers means fungal issues can strike quickly; ensure proper spacing and airflow around dense canopies of okra and melons as they begin their rapid growth phase this week.
- Take advantage of the current warmth to start indoors any crops not yet listed for sowing now, but focus your energy on moving out those tomatoes and peppers if you have them ready, or stick strictly to the harvest list like watermelon and cucumbers.
Sow this week
No direct sowing windows open this week.
Transplant this week
Nothing is due to go out this week.
Harvest soon
45 crops- Basil
- Borage
- 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)
- Honeydew Melon
- Leek
- Lima Bean
- Lisianthus (Prairie Gentian)
- Loofah (Luffa)
- Malabar Spinach
- Nasturtium
- Okra
- Ornamental Sweet Potato Vine
- Parsnip
- Pole Bean
- Potato
- Pumpkin
- Roselle (Cranberry Hibiscus)
- Scarlet Runner Bean
- Shiso (Japanese Basil)
- Summer Savory
- Sunflower
- Sweet Corn
- Sweet Potato
- Thai Basil
- Vinca (Madagascar Periwinkle)
- Watermelon
- Winter Squash
- Yellow Summer Squash
- Zinnia
- Zucchini
Seasonal tips
- Keep a close eye on pollinator-friendly flowers like Cosmos and Zinnia to ensure good seed set.
- Harvest bush beans and cucumbers frequently to encourage continued production throughout summer.
- Protect young transplants from late spring chill with row covers if an unexpected cold snap occurs.
- Plan succession sowing for cool-season crops now so they are ready as the weather cools in October.
Pest & disease watch
- Spider mites are becoming active in Columbus gardens as temperatures stabilize, particularly targeting the delicate leaves of shiso and garden verbena during dry spells.
- Late-season aphid colonies often build up on nasturtiums and cosmos; inspect undersides of leaves regularly since these plants can serve as unintentional traps for other pests.
- Powdery mildew is a rising concern for zinnias and sunflowers this week, especially if the humid weather persists without adequate air circulation between rows.
Watering this week
Water deeply in the morning to reduce evaporation and prevent fungal issues on leafy greens.
Save seeds from your best-performing varieties like French Marigold and Zinnia to start your next season's garden early.
Columbus gardening questions
3Can I still start basil seeds indoors now, or should I only transplant?
Since basil is on your harvest list and Columbus nights are warming up, it is best to transplant any started seedlings rather than starting new ones this week. If you do start fresh seeds, use a heat mat to compensate for the lingering chill that might occur after the average last frost date of April 21.
My pumpkins look small; should I fertilize them now?
With winter squash and pumpkin listed as harvest-soon crops, avoid heavy nitrogen fertilizer which encourages leafy growth over fruit development. Instead, apply a phosphorus-rich feed or compost tea directly to the base of the plant to support vine maturation before the first frost on October 24.
Are there any specific companion planting tips for the ghost peppers growing in my garden?
Ghost pepper plants (Bhut Jolokia) thrive when interplanted with basil or marigolds, which are also ready to harvest soon and can help repel common pests. Keep them away from brassicas if you have them nearby, as the strong scent of the peppers can sometimes confuse pollinators in dense plantings.
Other cities in zone 6b
12See the full zone 6b guide → · Plan your Columbus garden in SproutGuide →