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Allentown, PA Planting Calendar

The last spring frost in Allentown usually comes around Apr 12 and the first fall frost around Oct 28, a growing season of about 199 days. Start tomatoes indoors Mar 1 – Mar 15 and plant them outside Apr 26 – May 10.

Last spring frostApr 12
First fall frostOct 28
Growing season199 days

When to plant vegetables in Allentown

VegetableStart seeds indoorsPlant outsideFall crop
TomatoesMar 1 – Mar 15Apr 26 – May 10—
PeppersFeb 22 – Mar 8May 3 – May 17—
EggplantFeb 22 – Mar 8May 3 – May 17—
Cucumbers—Apr 26 – May 10—
Zucchini & summer squash—Apr 26 – May 10—
Pumpkins & winter squash—May 3 – May 17—
Green beans—Apr 26 – May 10Aug 5 – Aug 19
Sweet corn—Apr 26 – May 10—
BasilMar 15 – Mar 29Apr 26 – May 10—
LettuceFeb 15 – Mar 1Mar 15 – Apr 26Sep 2 – Sep 16
Spinach—Mar 1 – Mar 22Sep 2 – Sep 16
Peas—Mar 1 – Mar 22Aug 19 – Sep 2
Carrots—Mar 15 – Apr 19Aug 5 – Aug 19
Radishes—Mar 8 – Apr 26Sep 16 – Sep 30
BroccoliFeb 1 – Feb 15Mar 15 – Mar 29Aug 5 – Aug 19
KaleFeb 15 – Mar 1Mar 8 – Mar 22Aug 19 – Sep 2
Onions—Mar 15 – Mar 29—
Potatoes—Mar 22 – Apr 19—
Garlic——Oct 14 – Nov 18

Dates count from the median frost dates (2016–2025) for Allentown. In a cold spring, wait a week; in a warm one you can go a week early.

Month-by-month planting in Allentown

  1. JanuaryPlan, order seeds and prepare beds.
  2. FebruaryStart indoors: Peppers, Eggplant, Lettuce, Broccoli, Kale
  3. MarchStart indoors: Tomatoes, Peppers, Eggplant, Basil, Lettuce, KalePlant outside: Lettuce, Spinach, Peas, Carrots, Radishes, Broccoli, Kale, Onions, Potatoes
  4. AprilPlant outside: Tomatoes, Cucumbers, Zucchini & summer squash, Green beans, Sweet corn, Basil, Lettuce, Carrots, Radishes, Potatoes
  5. MayPlant outside: Tomatoes, Peppers, Eggplant, Cucumbers, Zucchini & summer squash, Pumpkins & winter squash, Green beans, Sweet corn, Basil
  6. JunePlan, order seeds and prepare beds.
  7. JulyPlan, order seeds and prepare beds.
  8. AugustPlant outside: Green beans, Peas, Carrots, Broccoli, Kale
  9. SeptemberPlant outside: Lettuce, Spinach, Peas, Radishes, Kale
  10. OctoberPlant outside: Garlic
  11. NovemberPlant outside: Garlic
  12. DecemberPlan, order seeds and prepare beds.

Tools for this season

Seed starting kitTrays with humidity domes for starting seeds indoors.See options on AmazonLED grow lightKeeps indoor seedlings short and sturdy.See options on AmazonFrost clothCovers tender plants on a surprise frost night.See options on AmazonSoil thermometerCheck the soil at 4 inches before you spread anything.See options on Amazon

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Frequently asked questions

When is the last frost in Allentown?

The median last spring frost is Apr 12 and the median first fall frost is Oct 28, based on 2016–2025 weather data.

When should I plant tomatoes in Allentown?

Start seeds indoors Mar 1 – Mar 15 and set plants outside Apr 26 – May 10, once nights stay above 50°F.

When should I plant a fall garden in Allentown?

Sow or transplant cool-season crops 6 to 12 weeks before the first fall frost (around Oct 28): broccoli and carrots first, lettuce, spinach and radishes last.

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