Jalapeño Plant Growth Stages | Life Cycle

The jalapeño is a variety of chilli pepper (Capsicum annuum) closely related to other familiar garden vegetables like bell peppers, habanero peppers, and banana peppers. Jalapeños are categorized as medium-hot peppers, with an average Scoville rating between 2,500 and 5,000.

Since all chilli cultivars — including the jalapeño — belong to the same species, there’s a lot of overlap in how these pepper plants grow and mature. While I specifically focus on the jalapeño plant growth stages in this article, you can apply much of the information to any chilli pepper growing in your garden!

Conditions for Growing Jalapeño Plants

Jalapeños are heat and sun-loving vegetables native to Mexico, so take that into account when planning your garden, with the ideal temperature for growing jalapeños being 70 to 90°F, they need direct sun. In most regions, jalapeños are transplanted in the spring after all risk of frost has passed and harvested from June or July.

These peppers need a bright location that receives at least 6 hours of sun per day. Insufficient sunlight will trigger spindly growth and limit fruit production later in the season. 

Wind can interfere with good pollination and so I recommend planting jalapeños somewhere that is partially sheltered or that lends itself to a temporary windscreen if necessary.

Plant jalapeños in very rich, well-draining soil with a pH level of 6.0 to 6.8. These peppers love organic material, and I like to amend my soil with aged compost or manure prior to planting.

Irrigate jalapeños with 1 inch of water per week on average during the growing season. Be careful not to overwater — well-draining soil is a big help — as soggy soil can wreak havoc on this plant’s roots. Aim to keep the soil consistently moist but never soaked, especially during hot weather.

Jalapeños are quite compact, even when compared to other pepper cultivars. You can easily grow these peppers in individual containers or a raised bed to make the most of your garden space. Containers should be 4 to 5 gallons in volume but make sure they have adequate drainage holes.

Growth Stages Of Jalapeño Plant

Jalapeños are perennial plants in their native climate. In most of the world, however, you’ll see these peppers grown as annuals.

According to Colorado State University, it takes an average of 110 to 120 days for jalapeño plants to go from germination to harvest. Peppers started from transplants rather than seeds will take between 75 to 85 days to produce ripe fruit.

1. Seed Germination

All jalapeño plants start as seeds. Jalapeño seeds are relatively slow to germinate, taking 21 to 28 days on average even in ideal conditions.

Whether started indoors or planted directly into the garden, jalapeño seeds require temperatures of 65 to 95°F to sprout. Conditions around 85°F produce the best results.

Because temperature is so important for germination, jalapeños are commonly started indoors in the spring. For example, in USDA zone 4, the soil temperature doesn’t get warm enough for jalapeño seeds until late May or even June. Sowing seeds indoors is the only way to achieve a reliable harvest in such climates.

2. Seedlings

Jalapeño sprouts emerge with two simple leaves already in place. These leaves are called cotyledons and are responsible for supplying energy throughout the germination and sprouting process. 

Did you know that cotyledons are actually part of a plant seed’s embryo? If you cut open a seed that is about to germinate — by the way, this experiment is much more effective using a seed larger than a jalapeño — you’ll be able to see the cotyledons curled up inside.

After a further 21 to 28 days, the first ‘true’ leaves appear. This foliage will resemble the normal leaves of a jalapeño plant albeit smaller.

It’s very common for gardeners to grow a variety of peppers in a single season. Keep in mind that chilli pepper seedlings look almost identical to each other at this stage, so I recommend labelling seed trays or beds to stay organized.

Jalapeno Seedlings with First True Leaves
Jalapeno seedlings ready to transplant

3. Vegetative Growth

About 30 to 60 days after germination, jalapeño plants are well into the vegetative growth stage. The average mature jalapeño plant will reach 2 to 3 feet tall and a little less wide. 

This part of the jalapeño life cycle is all about building a strong foundation to support flower and fruit production later on. A steady supply of nutrients, especially nitrogen, will encourage healthy stem and leaf development.

It’s possible for jalapeños to start flowering before the 60-day mark. While it’s tempting to let your plants do their thing, it’s best to pinch off any early blossoms to refocus energy on vegetative growth. Rest assured, more flowers will appear when the plant is better equipped to set fruit.

Note that container-grown jalapeños may not grow as vigorously as those planted in the ground. These peppers require a container that is at least 3 gallons in volume but I strongly encourage you to invest in a 4 or 5-gallon pot for the best results.

4. Flowering

Flowering begins 60 days after germination or 14 to 28 days after transplanting your jalapeños outdoors. This is an important transition in the jalapeño life cycle and I recommend switching from a high-nitrogen fertilizer to a high-phosphorus formula to support the coming changes.

Jalapeño plants produce white or yellow flowers that resemble those of tomatoes (the two veggies are within the same family, after all). These flowers generally appear near the top of the plant.

On average, jalapeño flowers only bloom for about 3 days before wilting and falling from the plant. But new flowers will continue to bloom throughout the growing season with the potential to produce fruit.

Several environmental factors can prevent or delay flowering in jalapeño plants. Drought stress is a common issue, especially in warmer climates. If you notice flowers blooming and then quickly drying up and falling from the plant, a lack of moisture might be to blame.

Daytime temperatures that exceed 90°F or nighttime temperatures that drop below 60°F can also cause existing jalapeño flowers to abort while preventing the development of new blossoms. This, in turn, delays pepper production.

5. Pollination

Since peppers are a type of fruit, successful pollination is required to create a crop. Everyday pollinators like bees and butterflies may pollinate your garden peppers. The wind can also play an important role.

Peppers are self-fertile, which means that a flower can be pollinated with pollen from the same plant. Some plant species have mechanisms in place to prevent this and increase genetic diversity. Jalapeño flowers, however, aren’t picky about where their pollen comes from.

Speaking of pollen sources, it’s possible for jalapeños to cross-pollinate with other chilli peppers. Many gardeners fear that this will affect the flavour of their vegetable harvest but that’s not the case. The fruit of pepper is entirely determined by the mother plant, not the pollen.

The only time you need to worry about cross-pollinating between cultivars is if you intend to collect seeds. In such situations, the Seed Savers Exchange recommends spacing pepper varieties at least 12 to 24 inches apart or using hand pollination to prevent unwanted crosses.

6. Fruit Development

After successful fertilization, a jalapeño flower will drop its petals and make way for fruit. The entire fruit ripening process takes about 55 days.

The very first stage of fruit development looks a lot like a fleshy, green flower bud. Each flower is capable of producing one pepper.

Over time, this immature fruit will lengthen and darken in colour. 

Early Jalapeno Fruit Development
Flower petals have fallen to reveal the young fruit

A good rule of thumb is to pinch off new flower buds once you have a healthy crop of immature peppers growing on one plant. 

Preventing any further fruit to develop allows the plant to prioritize quality over quantity until the current crop reaches maturity. You can then allow new buds to bloom once you start harvesting the first batch of peppers.

Jalapenos Plant Growth Timeline – Timelapse Video

The jalapenos plant in the timelapse video below was grown under artificial grow lights which reduced the overall growth timeline. During vegetation, the plant can be grown under a 24hrs light cycle which increases the growth rate, compared to a plant grown under natural light.

Growing Jalapeno Time Lapse - Seed to Fruit in 126 Days

When To Harvest Jalapeños

It takes about 55 days following pollination for a jalapeño flower to turn into a ripe pepper. That’s a total of between 110 and 120 days from germination. The harvest generally starts in early- or mid-summer and can continue until the first frost in fall.

The fruit of most jalapeño cultivars turns bright red when fully ripe. However, there are also a number of varieties that produce mature peppers that are purple, yellow, or green.

While the average ripe jalapeño is technically red, it’s very common for gardeners to harvest this pepper when it is still dark green. 

Still-green peppers can be harvested when they reach a mature size. For most varieties, this is between 3 to 4 inches long. Some jalapeños produce smaller or larger fruit, though, so I recommend double-checking what the mature fruit of your chosen cultivar should look like.

Green jalapeños have shiny skin that will ‘snap’ when broken or bitten. As jalapeños ripen on the stem, the skin tends to become leathery, with lateral lines that appear to look like cracks on the skin. This doesn’t mean that the pepper has gone bad, it is just fully mature and ready to pick.

Leaving jalapeños on the plant until they turn red often produces hotter and slightly sweeter peppers. The drawback is that it limits the plant’s ability to set new flowers and, therefore, continue producing fruit. Picking jalapeños as soon as they reach a mature size is the best way to increase the total harvest for the season.

Always harvest jalapeños using a clean knife or garden shears. I recommend leaving a short stem on each pepper as this helps them keep in storage.

Harvesting Jalapeno Peppers - Jalapeño Plant Growth Stages
Harvesting green Jalapeno peppers will encourage new flowers to set

FAQ Jalapeño Plant Growth Stages

Citations

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Ben's horticultural interest grew when graduating from Hertfordshire University in 1997. Having contributed to numerous publications including Better Homes & Gardens, Garden Design Magazine, and The English Garden. He is also the author of Propagating Houseplants Made Easy.