If your plants look stunted and its leaves exhibit chlorosis and lack vigour, yet you’ve done everything right and you can’t figure out why, it’s time to check the roots of your plants. If the roots are knobbly and have galls, you have a case of root knot nematodes in your soil. I have experienced this on a few occasions, fortunately in my planters and not in-ground. Read on to find out how to control root knot nematodes organically.
What are they? These plant parasites are microscopic roundworms that damage plant roots and feed on its vascular system. This causes growths to form, affecting the plant’s capacity to absorb water and nutrients.
Shrubs, trees and herbaceous plants are susceptible to root knot nematodes. These include begonia, azalea, hibiscus, gloxinia, hydrangea, impatiens, cyclamen, coleus, some cacti, rose, and edible plants like tomato, capsicum, chilli, eggplant, rosella, okra, cucumber, pumpkin, melons, Malabar spinach, passionfruit, banana, pineapple, sweet potato among others.
What are your natural options? Here’s how to get rid of root knot nematodes organically, you can consider using a mix of methods to improve efficacy rates.
Nematodes are microscopic worms that can cause major damage to African corn lily flowers These tiny pests attack the roots, disrupting the plant’s ability to take up water and nutrients Left untreated, nematodes can stunt growth, cause yellowing leaves, and even kill the plant. As a lover of African corn lilies, I’ve battled my fair share of nematode infestations. In this article, I’ll share the strategies I’ve found most effective for getting rid of nematodes and restoring the health of your African corn lilies.
Understanding the Threat of Nematodes
There are thousands of nematode species, many of which are harmless. However, certain types like root-knot nematodes target African corn lilies. When they feed on the roots, they create swollen knots or galls that restrict nutrient flow. Nematode damage also provides entry points for other diseases. An African corn lily experiencing a nematode infestation may exhibit
- Stunted growth
- Wilt and drooping leaves
- Yellowing or distorted foliage
- Small flowers and reduced blooming
- Overall lackluster appearance
If the infestation is severe, the plant may die. Nematodes prefer warm, moist environments and spread rapidly in sandy or loamy soils. Once introduced to your garden or container plants, they are difficult to eliminate entirely. But with persistence and repeated treatments, you can manage nematodes and restore your African corn lilies’ health.
Solarizing the Soil
One of the most effective nematode treatments is soil solarization. This technique uses the sun’s heat to kill nematodes and other soil-dwelling organisms. To solarize the soil around your African corn lilies:
- Water the soil thoroughly before covering it with plastic.
- Cover the soil tightly with clear plastic sheeting during the hottest months.
- Leave the plastic in place for 4-6 weeks.
- Remove the plastic and plant fresh African corn lily bulbs in the solarized soil.
The heat under the plastic can reach levels lethal to nematodes up to 6 inches deep. It also kills weed seeds and pathogens. Solarization works best for treating soil before planting.
Crop Rotation
Rotating other plant species in the same growing space helps break the nematode life cycle. Avoid planting African corn lilies or related bulbs in nematode-infected soil for 3-5 years. Instead, cycle in nematode-resistant plants like marigolds, radishes, onions, or grasses. This starves existing nematodes and prevents future populations from taking hold when you replant corn lilies.
Resistant Varieties
When selecting new African corn lily bulbs, look for nematode-resistant cultivars like ‘Goldfinger’ and ‘Everlast’. Resistant plants make it harder for nematodes to establish and spread. Introducing resistant varieties helps reduce the overall nematode levels in your soil over time.
Organic Amendments
Adding organic matter like compost, manure, or mulch creates a healthier soil environment that helps suppress nematode activity. The nutrients and microbial life in organic amendments bolster the plants’ defenses and make it tougher for nematodes to thrive. Spread 2-3 inches of compost or mulch around infected African corn lilies to reduce nematode populations.
Biological Nematicides
Beneficial nematodes and nematophagous fungi prey on harmful nematodes, providing natural biocontrol. Look for commercial nematode hunter products containing Steinernema or Heterorhabditis species. Follow label directions to apply the live beneficial nematodes to soil around infected plants. The predators will hunt down and destroy root-knot nematodes and other plant parasites.
Bottom Line
Nematodes don’t have to spell certain doom for your treasured African corn lily collection. Arm yourself with the right knowledge and products to fight back against these tiny invaders. Use multiple tactics like solarization, rotation, organic amendments, and biological control. With persistence, you can eliminate damaging nematodes and enjoy beautiful, nematode-free African corn lilies for years to come.
Grow biofumigant crops for root knot nematode control (Photo by
Brassicas such as Brassica rapa (field mustard) and Brassica juncea (mustard greens) have bio-fumigation properties and are effective at root knot nematode control when grown as a cover crop, however there are some other plants, like Tagetes patula (French marigolds), Tagetes erecta (Mexican Marigold) and oats, which are highly capable too.
How it works is it releases compounds to suppress pests and pathogens in the soil. It is effective when in its early flowering stages, plants are chopped or pulped and incorporated into the soil and watered. The soil needs to remain moist for a few weeks, and isocyanate gases are released by the plants as it breaks down.
Not all plants are susceptible to root knot nematodes. Through rotating the types of plants grown over two years or more, specifically incorporating plants that are not host plants, you can starve these nematodes. Root knot nematode resistant plants include corn, millet, grain sorghum, asparagus, and chrysanthemum and zinnia.
Add compost and organic matter
Good quality aerobic compost contains plenty of microbes. These include larger, predatory micro-organisms, including beneficial nematodes that can ingest root knot nematodes. By applying it directly as a top dressing or some prefer, compost tea, these microbes are introduced into the soil. Adding organic matter such as manure and leaves also encourages fungi, bacteria and naturally occurring good nematodes to inhabit soil.
In Singapore, you can get good quality compost from Soil Social, it is more pricey than other composts on the market, however it is aerobic and contains a high amount of beneficial microbes. I tried it and have seen improvements in my plants as soon as within a month. My stunted okra grew more lush and began fruiting more regularly.
You can also consider trying out this soil drench recommended by Jerry Coleby-Williams of Gardening Australia.
This method makes it very inhospitable for root knot nematodes, however it kills many organisms in the process, including pathogens, nematodes, weeds, and seeds. Soil solarisation involves laying clear (more effective) or black plastic sheets over wet soil for 4-6 weeks, therefore trapping heat and raising soil temperature. Nematodes are mobile, so this method will reduce numbers but it may not fully eradicate the population.
How To Get Rid Of Nematodes | Eliminate Bad Nematodes and Grubs Organically!
FAQ
What kills nematodes instantly?
How do you control corn nematodes?
What is a home remedy for nematodes?
What repels nematodes?
Do nematodes kill plants?
While many types of nematodes are beneficial to the soil, plant-parasite nematodes will attack and destroy plant roots, effectively killing the whole plant. The pests cannot be killed by most pesticides. So, gardeners will need to use gardening methods to make their soil as inhospitable as possible to the nematodes.
Are African corn lilies perennials?
A South African native, Ixia plant info indicates African corn lily plants are short-lived perennials and may perform as annuals, not returning after a hard winter. However, Ixia wand flower corms are readily available in garden centers and big box stores and are usually not expensive, so replanting is not much of a chore.
How do nematodes affect plants?
Wilting: Plants affected by nematodes may wilt, especially during the heat of the day, despite adequate watering. Yellowing: Leaves may turn yellow as the nematodes affect the plant’s ability to take up nutrients. Stunted Growth: Nematodes can hinder a plant’s growth if they attack the root system early in the plant’s development.
How do I get rid of nematodes in my garden?
Strategies such as crop rotation, adding organic matter, and fostering a diverse population of organisms can create a less accommodating environment for nematodes. I also utilize specific methods to target these pests without disturbing the beneficial nematodes or the soil’s health, which can be crucial for a thriving garden.