Ten Tips for Growing Grasses in Production

If you're bringing in liners, here are a few general tips to keep your grasses healthy and help you produce beautiful, finished plants.

1. Some like it hot, some like it cool—Are your grasses cool or warm season? It makes a difference. Cool- and warm-season grasses have unique dormancy and growth patterns. This affects your growing schedules, when to transplant, what time of year they finish, and when liners are available for purchase. Get a quick comparison between cool- and warm-season plants. We also have a page focused just on growing cool-season grasses.

2. Water correctly—Do not over water cool-season plants in the summer months when they are not actively growing. Do not over water warm-season plants in the winter months when they are dormant. Over watered grasses are susceptible to rotting and root damage. When you do water grasses and sedges, schedule it for early in the day. This allows the foliage to dry and reduces the risk for disease.

3. Fertilize when plants are actively growing—All methods will work (incorporation, topdressing, liquid feeding) if applied at the right time. Do not feed cool-season growers in the summer when growth is slow. Avoid fertilizing both warm- or cool-season plants late in the growing season─this can lead to weak growth and may leave plants susceptible to damage. A good time to topdress is just before, or at the time, plants break dormancy; however, keep fertilizer out of the crown to prevent burning.

4. Feed the right fertilizer and the right amount—Slower-growing plants, such as Sesleria and Carex species, require less frequent feeding. Fast-growing, native grasses can grow too quickly when given too much fertilizer. You may end up with weak, floppy plants. Be aware that Carex and native grasses can be salt sensitive.

5. Cleanliness is king—Use clean gloves and spray alcohol on pruners to prevent the spread of diseases. Remove leaf and soil debris in work areas to prevent contamination. By keeping areas and tools clean, insects and disease have less chance of moving in on your plants.

6. Prevent. Prevent. Prevent.—'Tis better to prevent problems than fight them. Remove weeds in and around greenhouses; weed seeds can transfer to stock. Use fans for air circulation and provide space around and under plants for uniform growth and drainage. Also, eliminate standing water. Standing water breeds pests and creates environments for water-borne diseases, moss, and algae.

7. Snag pests and take ‘em out—In the landscape, pests usually bypass grasses. But the nature of a nursery environment can invite a few to take up residence on your crop. Institute a regular scouting program to identify unwelcome creatures, and treat them with an appropriate product as soon as possible─before they become widespread. Be on the lookout for mealybug, spidermites, chinch bug, aphids, leafhoppers, thrips, and spittle bug.

8. Be a leaf detective—Get out your loupe and microscope. Inspect leaves and blooms for signs of disease. When in doubt, send samples to your local horticultural agencies for identification. Treat plants immediately.

Possible Diseases and Common Targets

• Anthracnose (Collectotrichum)—Miscanthus
• Bipolaris—Panicum
• Curvularia—Pennisetum, Eragrostis
• Gray Leaf Spot (Pyricularia)—Cortaderia, Melinis, Eragrostis
• Rhizoctonia—Most Carex, occasionally in old Pennisetum
• Rust (various strains)—Panicum, Calamagrostis, occasionally found on other species

9. Schedule regular fungicide applications—Identify the fungus and apply the right product. Continue with preventive fungicide applications every 10-14 days. To minimize resistance to products, rotate the fungicides in your schedule.

10. If you aren't sure, ask us—After 35 years, we’ve got insight into growing grasses. If you have questions, ask us. Growing problems? Ask us. Below are suggestions for the most asked-about plants and species.

Success with Selected Species

• Panicum virgatum—yellowing, rust, and slow emergence in spring are the most common concerns. Get prevention tips on our problem-free Panicum page.
• Carex—sensitive to watering, both over and under; possible root rot if too wet; avoid fertilizing in summer; no fertilizer in crown of plant. For in-depth info, go to our Considerations in Carex Container Production page.
• Helictotrichon sempervirens—narrow window to grow; grow in well-draining media; do not overwater; sensitive to high heat and humidity; shade in greenhouse in warm climates
• Miscanthus—overwatering can lead to root rot; responds well to cutting back; watch for Miscanthus blight—regular fungicide applications and strict cultural practices can help reduce or eliminate this problem
• Pennisetum alopecuroides ‘Hameln’ and ‘Little Bunny’—overwintering: if possible, grow under poly or in cold frame; avoid excess water; avoid late-season fertilizing
• Schizachyrium scoparium—fertilize carefully: timing is important to eliminate salt buildup; too much fertilizer may lead to weak, floppy growth; water early in the day