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SproutGuide

What to plant this week in Allentown, PA

Week of 2026-W37

As Allentown braces for its average last frost around April 3, this week marks the critical window to move your tender transplants out from protected starts into the warming soil. With night temperatures dipping near freezing before climbing higher by day, focus your energy on hardening off seedlings while preparing beds for immediate harvests of early summer crops.

The next 7 days

Allentown, PA
Today
9/12
80° 54°
Sun
9/13
81° 67° 💧67%
Mon
9/14
73° 57° 💧19%
Tue
9/15
74° 50°
Wed
9/16
80° 58°
Thu
9/17
82° 63° 💧16%
Fri
9/18
71° 59° 💧18%
Avg high 77°F Rain total 0.3" Humidity 72% Wind 4.7 mph
On the ground

Growing in Allentown right now

  • Allentown's clay-heavy soils tend to hold moisture longer in spring; incorporate generous amounts of compost or coarse sand now to improve drainage for your upcoming squash and bean plantings.
  • Take advantage of the city's urban heat island effect on south-facing slopes, where you can safely start sowing warm-season seeds like sweet corn and zucchini a week earlier than the surrounding Lehigh Valley countryside.
  • With rainfall often concentrated in short summer bursts, install drip irrigation or soaker hoses for your watermelon and cantaloupe patches to prevent leaf rot during heavy downpours common near the Lehigh River.
  • Monitor your garlic crop closely; while the plants are currently dormant, ensure mulch covers the bulbs adequately to protect against any late spring freeze events before growth resumes in earnest.
In the ground

Sow this week

No direct sowing windows open this week.

Move out

Transplant this week

Nothing is due to go out this week.

Coming ripe

Harvest soon

37 crops
  • Basil
  • Borage
  • Bush Bean
  • Cantaloupe
  • Cleome (Spider Flower)
  • Cosmos
  • Cowpea (Black-Eyed Pea)
  • Cucumber
  • Edamame
  • Fennel
  • Flour Corn
  • French Marigold
  • Garden Verbena
  • Garlic
  • Gourd (Ornamental/Bottle)
  • Honeydew Melon
  • Lima Bean
  • Loofah (Luffa)
  • Malabar Spinach
  • Nasturtium
  • Okra
  • Pole Bean
  • 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
Do this now

Seasonal tips

  • Succession sow bush beans or carrots every two weeks to extend your summer harvest window.
  • Pinch back the tips of basil and Italian herbs like summer savory to encourage bushier growth before frost.
  • Start planning your fall crop rotation; avoid planting nightshades in beds that held them last year.
  • Apply a light layer of compost around perennials now to strengthen roots for winter dormancy.
Keep watch

Pest & disease watch

  • Watch for early aphid colonies on newly emerging bean and squash foliage as temperatures rise above 50°F.
  • Keep an eye out for cabbage loopers if you have brassicas overwintered, though most gardeners here are just starting their main summer vegetable rotation this week.
  • Spider mites can become a problem in the drier pockets of Allentown's microclimates once May fully arrives.
Water

Watering this week

Water deeply in the morning to keep roots hydrated during heat waves while reducing fungal risks on leafy greens.

One more thing

Harvest watermelons when they make a hollow sound upon tapping, ensuring you get the sweetest fruit before the first frost hits.

Asked locally

Allentown gardening questions

3
Can I plant my tomato seedlings directly into the ground right now?

No, wait until after April 3 when the danger of frost has completely passed and soil temperatures consistently stay above 60°F. If you rush out before then, the cold nights will shock the plants and stunt their growth.

Should I start my sweet corn seeds indoors or sow them directly outside?

Sow your sweet corn and other warm-season crops like edamame directly into the garden after the soil warms up, as these plants do not transplant well from pots.

How do I protect my young pumpkins and gourds from late spring freezes?

Cover vulnerable seedlings with floating row covers or old sheets during any sudden temperature drops below 40°F, removing them once the sun warms the air in the afternoon.

Nearby

Other cities in zone 7a

12

See the full zone 7a guide → · Plan your Allentown garden in SproutGuide →