Fountain grass (Pennisetum spp) is a popular ornamental grass. This grass flowers in summer and its leaves bend outward and droop at the tips when mature, resembling a fountain.
Fountain grass can be planted in a variety of locations to provide a stunning backdrop to colorful flowers or soften the edges of pathways. This guide will help you to learn how to plant, grow and care for fountain grass to create your desired effect.
Fountain Grass Overview
Fountain grass can grow well in the zone from 4 to 9. It has fast and graceful growth. At first, new shoots emerge from the base of the plant forming a dense, clumping structure. These shoots form upright glass blades at first. As the blades continue to grow, they arch outwards creating a fountain-like appearance.
The flowering stage starts at mid to late summer. During this time, the plant produces flower spikes that rise above the foliage. The grass turns even more beautiful in fall as the foliage starts changing its color. The grass goes dormant during the winter and grows back by itself under the right conditions.
Fountain grass produces abundant seeds by itself. The seeds are present in the seed heads that mature and disperse seeds naturally. The seeds germinate in spring when temperatures warm up.
The seeds can also be dispersed by wind, water, and animals, which allows the fountain grass to colonize new areas and spread beyond its initial planting site.
Preparation of the Plantation Space
A proper planting space sets the stage for healthy growth and establishment of the fountain grass. The important factors to be considered while choosing the plantation space for the fountain grass are listed below:
Light: Fountain grass grows perfectly in full sun. A full sun exposure, 6 to 8 hours of direct sunlight daily, helps the plant to photosynthesize effectively. As a result, it gets sufficient energy needed for optimum growth and flowering.
Humidity: Fountain grass thrives in moderate to high humidity conditions. The fountain grass can also tolerate lower humidity but upon continual exposure to such an environment, the plant may get stressed and may not grow optimally.
Soil: Fountain grass prefers soil that drains well. This protects roots and makes them fully functional. Also, it prevents roots from rotting. Their growth does not demand excessively fertilized soil but grows best in moderately fertile ones. So, add organic matter like compost or well-rotted manure when planting.
Before plantation, clear the selected area. Remove any existing weeds and materials from the plantation site. Dig the planting holes twice as wide as the root ball of the fountain grass plant.
Plantation
You can plant fountain grass using either seeds or nursery-brought plants. The methods to plant them are briefly described below:
From seeds
If you are planning to grow fountain grass with seeds, you may have to start early for seeds to germinate before the early spring. Typically, you can sow seeds indoors 6 to 8 weeks before the last frost date in your area.
Make sure to keep the seed tray/pot in a warm, bright location with indirect sunlight. As they germinate, you can transplant them outdoors in the spring.
The grass plants can be planted in the early spring. For areas with mild winters, you can plant them in early fall.
Spacing multiple fountain grass plants properly is also important. Planting the fountain grass in containers is also possible. For this, choose a large container with drainage holes. The container should be big enough to accommodate the mature size of the grass and allow for good root growth.
A Guide On Varieties
Many varieties of fountain grass exist. Each variety has its own unique characteristics, some of the popular ones are listed below:
Hameln: Hameln is one of the hardiest and most popular varieties of fountain grass. It can grow up to a height of 14 to 24 inches. The flower spikes of Hameln are silvery-white in color whereas foliage is green.
Moudry: This variety has deep maroon-colored blooms. Moudry grows rapidly and grows up to a height of about 25 to 30 inches. The flower spikes are abundant in this variety.
Cassian: Cassian variety is similar in size to Hameln. Their blooms start off with a soft pinkish tint and mature to a creamy white color.
Little Bunny: Little Bunny is a dwarf variety of fountain grass. They grow about 12 inches tall. Their lower spikes are fluffy and are creamy white initially and age to tan as the season progresses.
Little Honey: Little Honey is the variegated version of Little Bunny. It is even smaller and reaches up to 8 inches tall. This variety produces tan or beige colored flower spikes and green foliages that turn to shades of golden-yellow, chartreuse, and sometimes hints of red or orange as they mature.
Watering Schedule
The newly planted fountain grass should be watered regularly. This provides adequate moisture to the grass for the establishment of the roots. Make sure the soil is consistently moist, but don't overdo it as this may make the soil waterlogged.
The established fountain grass is moderately drought-tolerant. So, deep-watering once a week is enough depending on weather conditions. During rainfall, adjust the watering frequency accordingly. Overwatering should be avoided as it can lead to root rot and other health issues.
Fertilization should be started in early spring as new growth begins. This supports the fast growth of the grass during the active growing season. Optionally, a light application of fertilizer can be applied in late summer or early fall to help maintain plant health going into the dormant season.
The use of balanced fertilizer is recommended formulated for ornamental grasses or a general-purpose fertilizer with an equal N-P-K ( (nitrogen, phosphorus, potassium) ratio. Organic fertilizers such as compost and well-aged manure can also be used for fertilizing.
Apply the fertilizer around the base of the plant, avoiding direct contact with the grass leaves as doing so may burn them. Water the grass thoroughly after applying fertilizer. This helps to solubilize the fertilizer, the nutrients can be then easily absorbed by the roots.
How To Care For Fountain Grass?
Pre-Plantation Care
As fountain grass thrives in full sun, it grows best when it receives at least 6-8 hours of direct sunlight daily. Make sure the soil is well-drained and amend heavy or clay soils with organic matter like compost to improve drainage and nutrient content.
Plantation Care
The newly planted fountain grass should be watered immediately for setting in the soil. During the initial days of planting, moisture should be consistently provided to help establish the roots.
Once established, fountain grass is moderately drought-tolerant. During this phase, water the fountain grass deeply but infrequently. Adjust watering based on weather conditions and soil moisture levels.
Cutting back fountain grass in late winter or early grass is a key practice. This helps the new growth to emerge. For pruning, gather the entire clump of fountain grass using gloves (fountain grass has sharp blades).
The fountain grass is then trimmed back to about 2-4 inches above ground level. All the foliage and flower spikes close to the ground are cut while pruning.
Sharp garden shears or hedge trimmers are used for the pruning process. The cuttings can be composted if they are obtained from a healthy plant.
Dividing
The main purpose of dividing the fountain grass is to avoid overcrowding. In this process, the entire clumps of the fountain grass are dug out and divided into smaller sections. Make sure that each division has a good amount of roots and healthy foliage attached.
Winter Care
If you have planted varieties that can sustain in the cold, you should apply a layer of mulch around the base of the plant to insulate the roots and protect them from extreme temperature fluctuations.
Apply a layer of mulch 2 to 3 inches in width to protect the fountain grass from the cold. Organic mulches like compost are best for mulching.
Container Care
Taking care of fountain grass planted in containers is different from the one planted outside. A well-draining pot mix and a pot with drainage holes are best for the growth of the fountain grass. The containers need to be placed in a location that receives full sun to partial shade.
Extreme winds can easily dry out the soil. So, it's better to keep fountain grass away from the wind. Regular feeding is needed in this case, make sure to use balanced fertilizer at least once a month.
In winter, move the container to a sheltered location. If they can't be kept inside, wrap them with insulation material like bubble wrap or horticultural fleece.
Pests and Diseases
Compared to taller fountain grass varieties, dwarf fountain grass is more resistant to pests and diseases. The invasive nature of taller ones makes them more susceptible to pests and diseases. Some of the common pests and diseases that have been reported in fountain grass are listed below:
1. Slugs
Slugs are commonly found in fountain grasses cultivated in moist and shaded areas. The damp conditions and the shelter provided by grass in such areas attract slugs. Slugs enjoy feeding on the leaf blades of the grass, damaging their appearance over time.
2. Snails
Like slugs, snails are also attracted to the moisture in damp areas. Snails feed on the leaves, stems, and sometimes even roots using rasping mouthparts. They can significantly damage young plants.
Snails also tend to leave behind silvery trails of mucus on plant surfaces reducing the overall ornamental value of the grass.
Spider mites pierce the cells of the grass and suck out its contents. As a result, yellow spots are visible on the surface of the plant. The characteristic sign of spider mite infestation is the fine webbing they produce on the leaves, commonly found on the underside of the leaves.
If the infestation is not controlled in time, the plants may weaken and in turn get susceptible to other diseases.
4. Scale Insects
Scale insects are commonly found on woody plants, but they are found to infest fountain grass as well. These insects settle on the blades and stems feeding on plant sap.
When feeding they secrete a sticky substance called honeydew, which can attract insects and diseases like sooty mold. Sooty mold appears as a black, powdery coating on the grass. Spider mites cause yellowing of the leaves and weaken the plant if the infestation gets severe.
5. Grass Lace Bug
Grass lace bugs are common invaders of ornamental grasses. These insects also feed on the sap of the grass leading to yellowish or whitish spots on the leaves. They excrete dark, tar-like droppings on the grass leaves, degrading the ornamental value of the grass. In extreme cases, the leaves start to curl or distort.
6. Nematodes
Nematodes feed on the root rather than the foliage. As a result of infection of nematodes, stunted growth, yellowing of leaves and even plant death can occur in severe cases.
7. Fungal Leaf Spots
Fungal infections are common in places with high humidity. The fungal leaves appear as small, circular to irregularly shaped lesions on the leaves. In some cases, the spots may have a wet, slimy appearance. When the infection gets severe, leaves may show overall discoloration.
8. Anthracnose Diseases
Anthracnose is a fungal disease that affects several plants severely. It is caused by fungi belonging to the genus Colletotrichum. The fungi appear as small, circular to irregularly shaped spots on the leaves.
The spots enlarge over time and cause damage to the leaves. In severe cases, anthracnose can also affect the stems and crown of the fountain grass.
The ways to manage pests and diseases that commonly interfere with the growth and development of fountain grass are listed below:
Many pests and diseases thrive in moisture. To reduce the moisture, water your fountain grass in the morning rather than at other times, as the water can be completely soaked up by the day's sunlight. Also, consider spraying the fountain grass with a strong jet of water to dislodge any insects from the leaves.
You can introduce natural predators like birds, frogs and beneficial insects that feed on the harmful ones. They can keep the invader's population in check.
Organic controls like beer traps or iron phosphate-based baits can control the spread of snails and slugs.
During hot summer months, cover the soil around fountain grass with clear plastic. This prevents the development of nematode's eggs on the top layers of soil due to extensive heat.
The spread of nematodes can also be controlled by nematode-suppressing cover crops or green manures like mustard or marigold.
As a last resort, use chemical insecticides or fungicides. Use pest and disease-resistant cultivars for the best control.
