Jalapeño Peppers

Jalapeños need full sun to blossom and set fruit. Choose a sunny place sheltered from the wind. They’re happy up to around 90°F (or 32°C).  Soil should be well-draining and rich in organic matter. In the spring, prepare the soil by working in a 3- to 5-inch layer of compost to a depth of 6 to 10 inches. Read more about preparing soil for planting.

When to Plant Jalapeño Peppers

Note: Many gardeners purchase transplants (small starter plants) from a local nursery garden center because their climate is not hot enough. Others start seeds indoors early, then transplant to their garden. Of course, if you’re in a hot climate (most southern states), just seed them outdoors!

If you are buying transplants, choose plants with green leaves and strong foliage. Avoid any yellowed leaves, sparse foliage, or spindly stems.

• For those starting seeds, sow indoors 8 to 10 weeks before your last spring frost date under grow lights. You’ll also need heat for seed germination—again, at least 70°F (21°C)—so the seed tray or pots should be on a heat pad. Of course, if you have a greenhouse, that’s the ideal solution. 
• To transplant (your own seedlings or starter plants from the nursery), wait until the weather has warmed to a daytime temperature of 70 to 75 degrees F. and nighttime temperature above 60 degrees F.

How to Plant Jalapeño Peppers

• If you’re sowing seeds into trays or containers to plant in the ground later, fill with seed-starting mix that is best for growing chili peppers. (Potting mixes are fine but hold onto moisture a little too well which peppers can’t stand). We recommend mixing a half ordinary all-purpose peat-free potting mix combined with half coir or coco fiber, with a good few handfuls of vermiculite thrown in for good measure.
• Plant seeds just 1/4 inch deep (you can just cover lightly with seed-starting mix). Water in and keep peppers moist (though never wet). Ensure your seedlings have good airflow and aren’t crowded.
• Once the seedlings are a good enough size and big enough to outgrow a tray, we will repot them and give them some liquid feed, using half-strength seaweed feed.
• Note: You can start with a bigger container if you wish to avoid repotting; bigger pots take more potting mix to fill, but they also need less watering. You can also decide to continue to grow your peppers in containers, especially if your region is temperate. But be sure your final container is about 5 gallons—big enough to grow through harvest.
• About 10 days before transplanting your jalapeño seedlings (or starter plants that you bought) outdoors, begin to harden off to better transition to the outdoors.  Learn how to harden off plants.
• In cold regions, you can use black plastic mulch to warm the soil prior to planting.
• Once soil and nighttime temperatures reach at least 60°F (15°C), transplant your seedlings (or purchased starts) outdoors, spacing them 14 to 24 inches apart.
• In cold climates, you can make slits in the black plastic to plant.
• Space plants 2 feet apart. Rows should be spaced at least 2 feet apart to provide good air flow.
• For transplants, dig a planting hole just deep enough to cover the root-ball of the plant and, when you set the plant in the hole, ensure the top of the root-ball is level with the ground surface. Do not plant deeply like tomatoes!
• A time-release fertilizer can be added to the soil before you backfill it and firm gently around the plant.
• Water thoroughly and mulch to hold in moisture.