Growing Lavenders: Tips For Healthy Roots
Lavender is a fragrant herb that is popular for its beautiful purple flowers and aromatic scent. They are fairly easy to grow, though providing the right care is key to getting healthy lavender plants with robust root systems. Here are some top tips for growing lavenders and encouraging strong root development.
Selecting The Right Lavender Variety
There are over 40 different lavender species, with hundreds of hybrids and cultivars. The variety you choose can impact how well it will grow in your climate and soil conditions.
English lavender (Lavandula angustifolia) is the most common type grown. It features fragrant gray-green foliage and violet flowers on long spikes. English lavender does best in hot, sunny locations with well-drained soil. The roots prefer dry conditions.
Spanish lavender (Lavandula stoechas) handles humidity better than English lavender. It has showy bracts on top of the flower heads. Spanish lavender adapts to more soil types but needs excellent drainage.
French lavender (Lavandula dentata) works well for cooler climates. It's more tolerant of winter wetness. The leaves are a fresh green and finely divided.
To get healthy roots, select a lavender variety suitable for your region's climate and soil type. Local nurseries can provide advice on the best cultivars to plant.
Providing Proper Sun Exposure
Lavenders need full sun to thrive. They require at least 6-8 hours of direct sunlight per day. With insufficient light, the stems stretch out and flowering is reduced.
Plant lavender where they will receive sunlight for most of the day. South or west-facing spots are ideal. Provide some afternoon shade in intensely hot climates to prevent stress.
If you only have a partially sunny area, choose a more shade-tolerant lavender variety like French lavender. Prune back leggy growth regularly to keep the plants compact.
Getting the right sun exposure encourages strong root establishment and growth. It also boosts flower production on the lavender.
Using Fast-Draining Soil
Lavenders do best in sandy, gravelly soils that drain rapidly after watering or rain. Wet soil is their enemy! Stagnant moisture around the roots leads to root rot and other diseases.
To prepare the soil, work in 2-3 inches of coarse sand or fine gravel. Raise garden beds 6-12 inches to improve drainage. Lavenders also thrive in rock gardens.
In clay soils, mound up the soil into berms or hills to plant lavender. This creates extra drainage around the roots.
Avoid compacted, soggy soils that hold onto moisture. Improve drainage before planting lavenders to prevent waterlogged roots.
Providing Adequate Air Circulation
Good air movement around lavender plants is essential for healthy roots. Stagnant, humid air increases the risk of fungal diseases taking hold.
Space lavender plants 18-24 inches apart for proper airflow. Avoid cramming them together or the lower leaves and roots may rot.
Grow lavenders near walkways or driveways where the breeze can circulate. Keep nearby plants pruned back to prevent overcrowding.
Remove weeds, fallen leaves, and debris that can trap dampness. Ensure your lavenders receive daylight breezes and air movement.
Lavenders prefer dry conditions and their roots will readily rot if overwatered. Follow these tips:
Allow soil to dry out between waterings. Wait until the top few inches are dry before applying more water.
Water early in the day so the soil dries out by nighttime. Wet foliage overnight encourages fungal diseases.
Thoroughly soak the soil when watering then allow it to dry down again. Avoid frequent shallow waterings.
Hold off watering after late summer rains/humidity when root rot is more prevalent.
Mulch around the plants to retain soil moisture between waterings. Lavenders thrive on sparse but deep watering.
Providing Proper Winter Care
Lavenders are at high risk of root rot and death during cold, rainy winters. Protect them by:
Pruning back in fall to prevent frost damage to wet foliage.
Adding gravel mulch to improve winter drainage if prone to standing water.
Covering with row tunnels, cloches, etc to shield from excess rain/moisture.
Avoiding fertilization in fall which encourages growth vulnerable to winter damage.
Cutting back any mushy, rotten roots in early spring and re-covering with dry soil/gravel.
Adjust care to prevent overly wet roots in winter. Take steps to improve drainage and protect from excess moisture.
Using Proper Fertilization
Lavenders have low nutrient requirements. Excess fertilizing can harm the roots and cause growth issues.
Use a low nitrogen, phosphorous-rich fertilizer (like bone meal) once yearly in early spring. Slow-release organic formulas are ideal.
Avoid high nitrogen fertilizers which cause excessive foliar growth and keep soil too damp. Never fertilize after mid-summer.
Raise lavenders in amended native soil or potting mixes tailored for herbs. Healthy soil provides sufficient nutrients without added fertilizer.
Pruning At The Right Time
Pruning lavender plants is vital for their health and productive roots. Here are some tips:
Prune annually in spring after new growth begins. Remove winter dieback down to healthy tissue.
Prune again after flowering in early summer. Cut back flower stems to just above the leaves.
Avoid shearing lavenders into tight balls. Selective pruning preserves growing tips needed for root growth.
Never prune lavenders in fall. This late growth is vulnerable to frost damage.
Remove dead/diseased stems anytime to prevent spreading.
Proper pruning at key times of year maximizes root health and productive, compact new growth.
Controlling Pests And Diseases
Left unchecked, lavender pests and diseases can damage or kill the roots. Watch for:
Root rot from fungus - improve drainage and avoid wet roots.
Weevils eating roots/leaves - use beneficial nematodes and remove larvae.
Whitefly infestations - use horticultural oil or insecticidal soap sprays.
Deer/rabbit damage - protect with fencing until plants are established.
Address any signs of trouble immediately to keep infestations from destroying the roots and overall health. Be vigilant!
Providing Adequate Root Space
As lavender plants grow over time, they need adequate room for the roots to spread out.
Crowded roots compete for resources and are more prone to diseases. Monitor root growth and provide space as needed by:
Transplanting small lavenders to larger pots every spring before roots encircle.
Dividing overgrown plants in early spring. Replant divisions 18-24 inches apart.
Adding supplemental irrigation, nutrients to support growth in bigger spaces.
Removing nearby plants encroaching on the lavender’s root zone.
Allowing lavender roots ample room minimizes competition and supports vigorous plants.
Using Proper Potting Methods
Lavenders grown in containers still need excellent drainage to avoid soggy roots. Here are some tips:
Choose containers with bottom drainage holes and raised feet to prevent water pooling beneath pots.
Use lightweight, porous potting mixes formulated for herbs and drainage. Avoid moisture-retentive soils.
Add extra perlite or sand to improve drainage. Top off pots with gravel mulches.
Avoid oversized pots. Only repot in slightly larger pots to prevent soil from staying too wet.
Ensure pots have drainage trays/saucers underneath to prevent rotting on damp surfaces.
Follow these guidelines when potting lavenders. Well-drained containers prevent kept roots for happy plants!
Propagating New Plants
Growing lavender from cuttings or layering preserves desired plant traits. Here are propagation tips for new, healthy lavender specimens:
Softwood cuttings - Take 3-4 inch cuttings from non-woody growth in early summer. Treat with rooting hormone and insert into sterile potting mix. Keep humid until rooted.
Semi-hardwood cuttings - Take fall cuttings from new growth that has just started to firm up. Root as above.
Layering - Bend lower branches down and cover partway with soil. New roots will form at the buried nodes. Clip off and replant once rooted.
Seeds - Sow seeds indoors 8-10 weeks before last spring frost. Transplant outside after hardening off.
With proper propagation methods, you can expand your lavender plantings and share this lovely herb!
Growing lavender successfully requires paying close attention to its cultural needs, especially around root zone conditions. By planting varieties suited to your climate, providing optimal sun exposure, and taking steps to prevent wet roots, you can have beautiful, thriving lavender plants for years of enjoyment! Which of these useful tips will you try in your garden? Let the aromatic blooms and fragrance of happy lavenders fill your landscape.