If you’re looking for a new flowering plant for window boxes, raised beds, and ornamental gardens, check out nemesia. This plant is less common than petunias, impatiens, and other summer annuals, so it will add a new layer of interest to your garden.

Nemesia plants only grow a few feet tall and become covered with flowers shortly after the weather warms. That makes them an excellent plant for adding a pop of color to late spring and early summer gardens. The plants can continue blooming throughout the summer if you choose a heat-tolerant variety and plant them in a location that’s protected from harsh afternoon sun.

I’ll cover how to grow nemesia so it provides you with beautiful and long-lasting flowers. You’ll learn how to select the right growing location, choose a variety that suits your needs, and address common problems.

What Is Nemesia?

Strumosa types shine in containers and sunny flower beds.

Nemesia is a genus of flowering plants that consists of around 70 different species. You can find various species available for sale at garden centers, but Nemesia strumosa and Nemesia caerulea are the most commonly available species. Numerous hybrids also exist and make up some of the newest cultivars.

Nemesia plants are also known as cape jewels or pouch nemesia.

Characteristics

They’re low-growing plants, but their flowers really steal the show.

Some nemesia species are tender perennials, and others are annuals. Regardless, most growers treat all types of nemesia as annuals and replant them each year.

The varieties commonly grown in stores typically grow between one and two feet tall. They produce multiple stems from the base of the plant, leading to a short yet bushy appearance. Each stem is covered with slender, lance-shaped leaves that appear in pairs.

The top of the stems eventually becomes covered with two-lipped flowers that slightly resemble snapdragon blooms. When the plants are in full bloom, the base of the plant is almost hidden by the flowers. 

The flowers vary in color depending on the variety and come in colors including purple, yellow, pink, and orange. Sometimes, the upper and lower lips are the same color, and other times, they’re two different hues.

Native Area

All varieties are native to places where the soil drains in seconds.

All types of nemesia are native to South Africa. They often grow in well-drained soils or in sandy and rocky coastal areas.

Planting

You can grow nemesia from seed or transplants. Some hybrid varieties are only available as seedlings, so transplanting is your only option for these types of nemesia.

Growing From Seed

A little warmth and patience bring green shoots quickly.

Nemesia is easy to grow from seed when you know the proper germination requirements. Since the plants don’t tolerate frost, start the seeds indoors about eight to ten weeks before your average last spring frost. If you want to grow another crop in the fall, start a second round of seeds in July.

Fill seedling containers with a well-draining potting mix, then place one to three seeds per cell. Cover the seed with a light dusting of soil and water well. Place the seeds in a location that’s between 65-70°F (18-21°C), and keep the soil moist.

You should see seedlings sprout within one to two weeks. As soon as you see them emerge, place the trays in a location that receives between 10 and 12 hours of daily direct light. Using a grow light is ideal if you don’t have access to a greenhouse or other warm, well-lit location. If multiple seeds germinate in a single cell, thin them so there is only one plant per cell.

When the plants have two sets of true leaves, they’re ready to plant in the garden. Just make sure you wait until the danger of frost has passed before placing them outdoors. You can keep growing them indoors for a few more weeks if the containers are large enough to support their growth.

Transplanting Seedlings

It tucks easily into window boxes without crowding the neighbors.

Another option is to purchase seedlings from a store and plant them in your garden, window boxes, or containers. The plants don’t grow very wide, so you can space them anywhere from 6 to 12 inches apart.

After planting the seedlings in the ground, keep them well-watered for the week following planting. You can ease off the watering after they settle into their new home.

How to Grow

Nemesia is relatively easy to grow both in the ground and in containers. Follow these care tips for healthy plants.

Light

Bright mornings bring out the best flower show.

Nemesia generally prefers full sun, and lots of light leads to plants full of flowers. If you live in zones seven and above, provide the plants with afternoon shade to protect them from intense heat. As long as the plants receive at least six hours of bright light, they’ll remain happy.

Water

The plants are a little drought-tolerant but love a steady drink.

These flowering plants require a moderate amount of water. They can withstand short dry spells but won’t hold up well in an extended drought. In most locations, watering one to two times per week will keep the plants happy, but checking the soil is the best way to determine when to water. If the top inch feels dry, grab your watering can or hose to moisten the ground thoroughly.

Watering near the base of the plant is always preferred to overhead irrigation. Keeping the leaves dry limits the likelihood that the plants will develop fungal diseases.

Soil

It grows happiest in loose, well-drained beds or containers.

Nemesia grows best in well-draining soil. If your soil is compacted or poorly aerated, loosen it with a digging fork before planting. Adding compost will also improve drainage and help the plants thrive.

If you’re growing one of the flowering plants in a container, choose a well-draining potting mix designed for bedding plants. Mixes made from compost mixed with peat moss or coco coir are a good option.

Temperature and Humidity

It blooms best in the sweet spot of spring temps.

Nemesia doesn’t tolerate below-freezing temperatures, but it also struggles in high heat. The plants grow best between 50-75°F (10-24°C), so the ideal growing time depends on where you live.

In zones 8 and above, plant immediately after the last spring frost so you can enjoy flowers before high temperatures arrive. The plants will often fade in the summer, but you can replant in late summer for a flush of fall blooms.

Gardeners in zones 7 and below can often enjoy the plants’ flowers throughout the summer. Planting in an area with afternoon shade will increase the chances that the plants will remain healthy.

Humidity levels aren’t a big deal since nemesia can tolerate a wide range of air moisture levels.

Fertilizing

Monthly feeding helps keep the blooms coming strong.

Nemesia doesn’t require fertilizer to grow and produce flowers, but adding nutrients once a month will help the plants continue to bloom throughout the season. Choose an organic fertilizer designed for flowering plants and apply it according to the product instructions.

Maintenance

Minimal care is required; only watering and optional deadheading are needed.

Nemesia plants require minimal maintenance aside from regular watering. Deadheading faded flowers encourages the plants to produce new blooms, but it isn’t necessary.

Propagation

If you want to grow new nemesia plants, there are a few ways you can propagate existing plants. Saving seeds and rooting stem cuttings are the two most common methods for propagating plants.

Saving Seeds

Wait for the brown pods to mature before collecting the seeds carefully.

The first step in saving seeds is waiting until the plants have developed mature seeds that you can collect. Look for small brown seed pods and gently cut them from the plants. Place them in a cool and dry area indoors to allow them to finish drying.

Once they’re fully dry, you can break the pods open to reveal the small, individual seeds. At this point, you can plant the seeds just like you would if you purchased them.

Propagating From Stem Cuttings

Dip cuttings in a rooting hormone for stronger root growth.

Taking and rooting stem cuttings is another way to propagate nemesia. This method produces plants that are identical to the parent plant, making it the best method for propagating hybrid varieties.

Start by looking for healthy, non-flowering stems. Use a pair of sharp and clean shears to take a cutting that’s at least three inches long. Remove the lower leaves, dip the bottom end of the cutting in a rooting hormone, then place the bottom inch of the cutting in a well-draining material. You can use perlite, peat moss, or soilless potting mix.

Cover the cuttings with a clear plastic dome or plastic bag to trap moisture. This will prevent the cuttings from drying out while they’re developing roots. Place the cuttings in a cool area out of direct light and keep the growing material slightly moist.

The cuttings should form roots in a few weeks. If you gently tug on the cutting and stay in the container, it likely has roots. At this point, you can plant it in your garden.

Popular Varieties

You can find dozens of different types of nemesia, including new hybrids and old cultivars. Here are some of the most popular varieties.

‘Blue Gem’

Bright blue petals with splashes of yellow brighten any spot.

A type of Nemesia strumosa, ‘Blue Gem,’ features blue flowers with yellow and white splotches on the middle of their flower lips. The plants grow between 6 and 12 inches tall and wide, so they’re a good option for compact containers.

‘Aromance® Mulberry™’

Sweet-scented blossoms attract friendly pollinators all season long.

This variety of Nemesia fruticans features bright fuchsia flowers with small pops of bright yellow. They grow between 12 and 18 inches tall and continue to bloom as long as the weather doesn’t get too hot. The flowers have a pleasing fragrance and attract numerous pollinators.

‘Berries and Cream’

Soft and deep purples make each flower stand out beautifully.

This variety features bicolor flowers with light violet lower lips and deep purple upper lips. The plants grow about a foot tall and work well in gardens and containers.

‘Juicy Fruits™ Kumquat’

There is no need to deadhead for nonstop yellow and orange blossoms.

The Juicy Fruits™ collection of nemesia plants is a group of hybrids that remain less than a foot tall. The compact plants become loaded with flowers that continue to appear without deadheading. This variety features flowers in shades of bright yellow and orange.

Common Problems

Nemesia doesn’t experience too many issues. Keeping an eye out for the following problems will help keep your plants healthy.

Diseases

Mild fungal infections make plants look rough, but they usually recover.

When plants become covered with a powdery white coating, they’re likely infected with powdery mildew. This fungal disease infects a variety of garden plants, including nemesia.

Moderate cases of the fungus make the plants ugly but don’t cause much harm. If the disease progresses and becomes severe, it can limit photosynthesis and reduce growth and flowering.

Paying attention to the environment can help prevent powdery mildew. Ensure that plants are spaced far enough apart to allow air to circulate between them, and position your nemesia in a location with at least six hours of daily sunlight.

You can try to treat this fungus, but it’s often unwarranted in the home garden. As long as infections aren’t severe, your nemesia will likely rebound. 

Root rot can also be an issue in overly wet soil. Heavily affected plants should be removed from the garden. Those who are just taking on the problem should be removed from their location and their roots inspected. Remove any brown and rotted roots and replant, waiting for the soil to dry to water again.

Heat Stress

Giving some shade keeps plants happier when the temperature soars.

While this isn’t a pest or disease, it’s a common issue nemesia growers face. These flowering plants don’t tolerate frost, but they also become stressed by high temperatures. Once the days consistently exceed 80°F (27°C), the plants struggle to remain healthy.

Yellow and brown leaves, plus a lack of vigor, are common signs of heat stress. You can help your plants last longer into the summer by planting them in an area with afternoon shade and providing plenty of water.