Caring for hostas involves a bit of effort, particularly when preparing them for their dormant period.
Once their leaves die back in the fall, it’s advisable to clear away the old foliage. While it’s possible to leave the foliage until spring, removing it in the fall is beneficial for preventing pests and diseases. However, it’s important to note that hosta foliage should not be added to compost piles.
Read also: Growing and Planting Hostas.
Hosta in the fall.
1. Cut back the hosta
Begin your fall hosta care by pruning as soon as their leaves start to wither. Pruning is crucial at this stage.
Start by cutting back the leaves and stems in early fall, particularly when the foliage turns yellow. Carefully trim the leaves, leaving about an inch of the petiole above the ground. It’s important to avoid cutting too close to the rhizome to prevent damage that could lead to rot during the winter.
Additionally, don’t let the fallen leaves remain near the plant. After pruning, remember to clean and sterilize your tools thoroughly. Finally, ensure that all removed leaves are disposed of away from your garden to prevent disease spread.
Read more: How to cut back hostas in the fall?
2. Keep soil slightly moist
Even after removing its leaves, it’s essential to continue watering your hosta. The plant remains active and utilizes water throughout the winter, drawing on moisture stored in its tissues during its dormant phase.
To ensure healthy growth, the soil around your hosta should be kept consistently moist, but not overly wet. The top inch of soil should never completely dry out.
The good news is that fall typically brings enough rainfall to naturally maintain soil moisture. However, in the absence of rain, you’ll need to manually water the hosta. Regularly check the soil’s moisture level, and if you find the top inch dry, gently water the plant. A guideline is to use no more than a gallon of water per watering session to avoid over-saturation.
3. Mulch your hostas
An essential step in hosta care is mulching, which offers several benefits, including retaining soil warmth for an extended period. This extra warmth is crucial as it aids in better overwintering of the plants. Mulch also helps in maintaining soil moisture.
While various materials can be used for mulching, compost is highly recommended. However, ensure you use high-quality compost from reputable suppliers to avoid harming your plants.
A 2-inch thick layer of mulch is ideal, providing all the necessary benefits without hindering air circulation. A thicker layer might lead to insufficient air reaching the soil, potentially causing diseases.
Remember, if you cover the hosta’s crown with a thin layer of compost for winter protection, it’s important to remove this layer early in spring.
Spread the mulch around the plant, extending 2-3 feet in diameter, depending on the size of the hosta. This ensures adequate coverage for optimal plant health.
Read more: 4 Best Mulch for Hostas.
4. Protect your hostas from voles
Voles typically don’t bother hostas during their active growing season. However, in colder months when food is scarce, they tend to feed on the hosta rhizomes. This can lead to hostas not emerging from dormancy in spring or growing very slowly. While frost damage might be suspected, often the real culprit is voles damaging the roots and crown, which can be detrimental to the plant’s recovery.
To safeguard your hostas against voles, a castor oil solution is highly effective. Here’s how to prepare it:
- Take a five-gallon container and fill it with water.
- Add a third of a cup of soap to the water and stir thoroughly.
- Mix in three cups of castor oil until well blended.
- Apply the solution around each hosta bush, using one gallon per plant. For larger plants, you may use up to two gallons of the mixture.
This treatment is effective because voles are repelled by the smell of castor oil, keeping them away from your hostas.
Read more: Do I need to do anything to my hostas before winter?
5. Avoid using fertilizer
It’s crucial not to fertilize hostas in the fall. Fertilization at this time can disrupt their natural hibernation cycle, potentially triggering new growth. This untimely growth is susceptible to frost damage, which can be fatal for the plant.
Mineral fertilizers, known for their quick action and potency, should be used with caution. The latest advisable time to apply such fertilizers is by July. In contrast, slow-release fertilizers are more suitable for hostas and should be applied once annually, preferably in spring.
Organic fertilizers, like compost, can be safely used in the fall. They can serve as a nutrient-rich mulch or be incorporated into the soil during planting to improve soil quality. This approach nurtures the hostas without encouraging inappropriate growth during the colder months.