How to Plant, Grow, and Care For Pentas
Charming and vibrant, pentas light up the garden and lure pollinators with their abundance of nectar. Beekeeper Melissa Strauss has the information you need to grow this bee and butterfly favorite.
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Calling all butterfly enthusiasts! If you’re looking for a low-maintenance flowering plant that is certain to draw your winged friends to the garden, you’re in the right place. Adding this plant to your pollinator patch is a wonderful way to provide food for beneficial insects.
Colorful clusters of flowers bloom repeatedly, making these a constant source of color in the landscape. These tough tropical plants don’t like cold weather, but they make great annual additions in cool climates.
Pentas is a delightful flowering plant that is an excellent pollinator garden addition. Their long blooming habit means food for pollinators and flowers for you, from spring to frost. They are easy to care for and highly disease resistant. Let’s look at pentas and how to grow these nectar-rich plants in your flower beds.
Overview
Plant Type
Pentas lanceolata
Family
Madder
Genus
Pentas
Species
Lanceolata
|
Native Area
Africa, Madagascar, Arabian peninsula, Comoros
Exposure
Full sun
Height
2’-3’
Watering Requirements
Moderate
|
Pests & Diseases
Mites, caterpillars, aphids
Maintenance
Low
Soil Type
Moist, fertile, well-drained
Hardiness Zone
8-11
|
What Is It?
Pentas are flowering annuals or perennials, depending on your climate. They are perennial in tropical climates, where they bloom nearly year-round. In cooler climates, they are annuals that bloom through most of the spring, summer, and fall.
Often a staple in pollinator gardens, the flowers are very appealing to beneficial insects. Butterflies and hummingbirds are especially attracted to the red varieties. They provide an excellent food source for these pollinators, and they look good doing it.
From an ornamental standpoint, these are fantastic plants. They are colorful and low-maintenance and rarely have any issues related to pests or diseases. Let’s take a look at lovely pentas and how to grow these flowers in the garden.
Native Area
Pentas are tropical plants. They are native to tropical regions in Africa, Madagascar, the Comoros, and the Arabian Peninsula. The shrubs typically grow in grasslands and in their native environment, can grow up to six feet tall and wide. Much larger than they will grow as an annual or even a perennial in cultivation.
Characteristics
Pentas are small to medium-sized, and shrubby. They are sometimes referred to as Egyptian starcluster because of the appearance of the flowers. The blooms are small and appear in umbel-shaped clusters. Each flower has five petals that form a star shape. The name of the plant comes from the Greek word for a series of five, referring of course to the arrangement of the petals.
The plants mature to between one and four feet tall depending on the variety. They are many-branched and shrubby, with dense, lanceolate leaves. The dark green leaves have a covering of short, fine hairs.
These plants bloom in a variety of colors, including white, pink, purple, lavender, and red. They have no detectable fragrance. They are not self-cleaning, so deadheading is a must if you want them to keep blooming.
Planting
You can grow these plants in containers or in the ground. They don’t like to dry out so make sure that you have an irrigation method nearby. They will grow into small shrubs, reaching two to three feet in a year, as annuals. As perennials, they can grow as large as four feet tall and wide, so in warm climates be sure to give them the space to spread out.
As I mentioned, these make a great addition to the pollinator garden. They are not native to the United States, but they don’t carry much risk of disease, and they are a great source of pollen and nectar. Adding these to your pollinator patch will make the butterflies happy. Because of their need for moisture, drainage is important, so keep that in mind when choosing a location.
Transplanting
Pentas are best transplanted in the spring. This gives them the longest bloom time as an annual. I always recommend watering your plants well before transplanting. Hydrated roots are more flexible, and hydrated foliage withstands shock better.
Prepare your location and amend the soil if needed, digging holes at least 12 inches apart for these plants. Dig holes slightly larger than the root ball. Loosen the root ball gently and remove it from the pot, position it in the hole, and backfill. Tamp down the soil lightly to remove air pockets, and water your plants in.
Growing from Seed
Pentas transplant well, so there is no reason to wait until the soil warms up to sow these seeds. You can start your seeds indoors about seven or eight weeks before the last anticipated frost date. This will give you a head start on the blooming season.
Fill your seed trays with a moist, high-quality potting mix. These seeds need light to germinate, so you don’t want to plant them deeply. Press them lightly into the surface of the soil, and don’t cover them.
Place your seeds in a bright location to aid in germination and keep them warm and moist. You can cover your seeds with a plastic cover or plastic wrap to create a greenhouse effect, but remove it once the seeds have sprouted. Harden off your seedlings for ten days before planting in the ground or pots.
How to Grow
Growing pentas is not challenging, but they do require some consideration in terms of moisture. Overall, they are low-maintenance and have very few problems to contend with. They work well in most spaces with sufficient sunlight. You can even grow them indoors if you have a sunny window.
Light
Full sun is best for these flowers, which means at least six hours of exposure daily. While they can grow in partial shade, they tend to become leggy and unattractive. Not to mention, they won’t bloom nearly as well.
In cool climates, it would be difficult to give your pentas too much sun. In warm climates where they will have to brave the heat of midsummer, some afternoon shade will keep them looking fresh.
Water
Once they set down roots, pentas will be somewhat drought tolerant. They do, however, prefer moist soil, and will look their best if they receive water regularly. This is especially true during the hot summer months and in times of little rain.
If you notice your leaves and flowers looking droopy or wilted, they need supplemental water. In containers, these will need watering on a daily to every other day basis in hot weather.
Soil
Because they like moist soil, it’s best to plant these in soil that holds some moisture. If you have sandy soil, you can amend it with some organic compost or garden soil. They also appreciate fertile soil, so the compost will help increase the nutrient density of the soil.
Since they prefer plenty of moisture, they also need soil that drains properly. Soggy feet often mean root rot for pentas. The ideal pH for these flowering beauties is slightly acidic to neutral. A pH between six and seven is perfect.
Temperature and Humidity
Hot and humid are the conditions under which they are happiest. As natives of Africa and Arabia, pentas plants prefer warm weather. They will begin to go dormant when temperatures drop below 55° F. When it comes to humidity, these will take very high levels in stride. Levels as high as 95-98% are perfectly fine.
Fertilizing
Get off to a strong start by working some fertilizer into the soil at planting time. A balanced formula is best for this purpose. As blooming time approaches, start using a bloom-boosting fertilizer once per month. A formula that is high in phosphorus will keep those flowers blooming.
Maintenance
Early in the season, pinch your pentas back to promote branching. This will give them an attractive, shrubby shape with plenty of branches on which to bloom. Keep watering regularly and fertilizing monthly for an explosion of color. Deadheading is important to maximize flowering.
Propagation
Propagation is a simple process. You can propagate by seed, which we have covered, or by cuttings. Let’s go over a simple method of propagation by rooted cuttings. You may want to propagate your plants to spread them to other parts of the garden or share them with gardening friends.
1. Timing is Important: You want to take your cuttings while the plant is actively growing. A new branch will root better than a mature one.
2. Choose the Right Medium: A well-draining potting soil that holds some moisture is going to be best for this process. Delicate new roots will quickly suffocate in heavy, dense soil types. Fill small pots of cells with your moist potting mix.
3. Take Your Cuttings: Cut branches about four inches long, slicing at a diagonal at the bottom for maximum rooting space. Then remove the flowers, if they exist, and most of the leaves. Leave a couple of leaves for the sake of photosynthesis.
4. Plant the Cuttings: Rooting hormone is optional but helpful and recommended. Use the end of a pencil to make holes in your soil. Place the cutting in the hole and lightly firm the soil around the stem to hold it in place.
5. Cover Up: Cover your cuttings with plastic or a clear bag to hold in moisture and create a tiny greenhouse. Punch a hole or two in the plastic for ventilation.
6. Pick a Location: Place your cuttings in a warm location with bright but indirect light. Some direct light is ok, but too much will stress your plant babies. Leave them alone, only disturbing them to keep the soil moist. Your cuttings should root in about six weeks. New growth will indicate success!
Popular Varieties
Lucky Star Mix
botanical name Pentas lanceolata ‘Lucky Star’ Mix | |
sun requirements Full sun | |
height 12”-16” | |
hardiness zones 2-11 |
The ‘Lucky Star’ series is exceptionally popular for its incredible blooming habit. This variety flushes with flowers early in the season and stays compact as a result. Deadhead regularly for continued blooms well into fall. The mix is a combination of all colors in the series, which includes white, red, pink, and violet. Plant them all for a dynamic addition to beds and borders.
Falling Star Pink Bicolor
botanical name Pentas lanceolata ‘Falling Star Pink Bicolor’ | |
sun requirements Full sun | |
height 8”-10” | |
hardiness zones 2-11 |
Small but mighty, ‘Falling Star Bi-color Pink’ might be my favorite variety. Their diminutive size makes these a great, colorful ground cover for low-traffic areas. It has a bit of a trailing habit, which is unique. The flowers are perfectly lovely, pale pink stars with rose-colored centers.
Starcluster White
botanical name Pentas lanceolata ‘Starcluster White’ | |
sun requirements Full sun | |
height 18”-22” | |
hardiness zones 2-11 |
This newer variety debuted in 2014 and truly lives up to its star power name. The flower clusters are large masses of perfectly star-shaped, pure white flowers. It’s a mid-sized, small shrub that works well in a wide range of spaces. The blooms are particularly striking.
Graffiti Lipstick
botanical name Pentas lanceolata ‘Graffiti Lipstick’ | |
sun requirements Full sun | |
height 12”-16” | |
hardiness zones 2-11 |
Picture the perfect shade of a bold, pink lipstick in flower form. Compact and extra floriferous, this variety has bold and eye-catching blooms. It makes a wonderful border, plant this one next to your front walkway to greet guests with its cheerfully bright shades of pink and green.
Common Problems
Pentas are easy-going in the garden, with few pests or diseases to look out for. They truly are tough plants. Keep an eye out for these things, just in case. They are sensitive to cold weather, but that doesn’t affect the season as long you wait for the soil to warm up before planting.
Pests
Pests will mostly leave this one alone, with just a few exceptions. Because it is a butterfly attractor, caterpillars may munch on the leaves now and then. How you handle this depends on your purpose in planting pentas in the first place. If you want to attract butterflies, you have to live with the caterpillars. Otherwise, manual removal is an effective and safe way to get rid of them without poisoning pollinators.
Spider mites and aphids are the other pests that can present an issue for this plant. For a mild infestation, spray your plants with a strong stream of water. This will knock many of the insects off. If you can’t eliminate them this way and natural predators don’t help, neem oil will get rid of them. Make sure to spray it in the evening so that it dries before the pollinators visit in the morning.
Diseases
The only disease of any note to affect pentas is bacterial leaf spot. The symptoms include yellowing leaves or leaf drop, as well as water-soaked spots that turn brown and black on the leaves. Prevention is the best way to handle this disease because once you have it, those plants have to go.
When you bring your plants home, be sure to inspect them for any potential diseases or infestations. Most of these things come in on other plants, so inspection of any plant you bring into the garden will go a long way toward prevention.
Frequently Asked Questions
Are Pentas Toxic to Animals or Humans?
Not at all. All parts of the plant are perfectly safe for your pets and for people.
Are They Considered Invasive?
For the most part, no, they are not invasive. Under ideal conditions, they can self-seed and spread, but they are typically not aggressive.
Why Are My Leaves Turning Yellow?
Yellow leaves are usually an indication of over or under-watering. If the leaves look dry and wrinkled, they need more water. If the leaves look droopy and mushy, that’s a sign that they are getting too much water.
Final Thoughts
Pentas are wonderful small shrubs that bring tons of color to the garden without making a fuss. Additionally, they are a major asset in the pollinator garden. As a border, a drift, or in a container, you’ll love the mass of star-shaped blooms that come from this plant. Give them full sun and plenty of water, and watch these beauties bloom for many months.