The Ultimate Guide to Fertilising Hostas: When, What, and How to Feed Your Plants
- John Plant
- Mar 28
- 6 min read
Updated: Apr 7
Hostas are a perennial favourite among gardeners due to their exotic, lush foliage and exceptional shade tolerance. Furthermore, they offer a diverse array of leaf shapes, sizes, and colours. To ensure the optimal growth and appearance of Hostas, it is crucial to supply them with the proper nutrients through appropriate fertilisation practices.
This blog aims to provide comprehensive information regarding the proper feeding of Hostas.
Before spending money out on a whole range of expensive proprietary fertilisers, consider the organic approach to keeping your Hostas healthy, first.
For Hostas to thrive, they need constant moisture and soil rich in organic matter. In dry soils, they grow slowly, produce fewer leaves, and look less lush, especially in summer. The location is crucial, but you can enhance it by incorporating plenty of compost into the soil. This improves fertility, water retention, and drainage during heavy rains.
Partially decomposed mulch enriches soil with organic matter. Fresh wood chips can harm Hostas unless paired with nitrogen fertiliser. Better options include aged Dark Bark, aged manure, or compost. Some garden centres offer bagged mixtures of compost and aged bark. Fresh bark ties up nitrogen as soil bacteria decompose it.
Adding the right amount of organic matter reduces the need for fertiliser for your Hosta. Use organic options like chicken manure, following label instructions to retain nutrients. Prepare Hosta beds this way and you'll see the best growth in moist areas. Plant larger varieties there as they need more moisture.
Hostas that are planted in the ground and mulched regularly with a good organic material, may not even need fertilising at all.
So! When is the best time to feed my Hostas?
From late summer, through Autumn and Winter, into the spring you shouldn’t have fed your Hostas. Wait until Spring has sprung. Just about the time your Hostas are pushing up their new spring growth, the leaves for the season ahead, then this is the time to start feeding.
Early Spring
Hostas begin to emerge from dormancy in early spring. The first appearance of spike-like shoots is a clear indication that spring has arrived. This period is optimal for applying the initial round of fertiliser to encourage robust growth and development.
During this phase, Hostas are delicate, necessitating the application of a light fertiliser while ensuring it does not contact any foliage. It is advisable to sprinkle a top dressing around the base of the plant and lightly incorporate it into the soil with caution to prevent damage to the new foliage.
Late Spring to Early Summer
During late spring to early summer, when plants experience significant growth, a second application of fertiliser may be administered. Fertiliser should only be applied if the plant exhibits signs of weakness or underdevelopment. However, in cases of poor soil quality or sandy soil, a second dose may be necessary. If uncertain, it is advisable to apply another light feed around the base of the plants.
Mid to Late Summer
During mid to late summer, Hostas exhibit slower growth but still necessitate nutrients to preserve their vigour. If your plants appear healthy and you are confident in the quality of your soil, it is advisable to forgo this round of fertilisation. When the plants die back, sufficient organic material will be recycled by the plant to ensure readiness for the following spring. Do not feed when foliage starts to die back.
Before anything else, we start with improving the soil with compost. Incorporating compost into the planting holes when planting, is the best fertiliser you can start with. At this point the addition of well-rotted organic manure and or a powdered or granulated fertiliser can be used. However, if you want your Hostas to grow to the best of their ability, a balanced fertiliser applied regularly, is key.
The type of fertilizer to use depends on the individual gardener's preference. A slow-release granular fertiliser can be used in spring to support plant growth. A typical granular fertilizer has an NPK ratio of 10-10-10, representing Nitrogen, Phosphorus, and Potassium. Slow-release fertilizers provide nutrients gradually with each watering or rainfall, lasting about one to two months based on temperature and water application. It is essential to keep granular fertilizer away from the leaves and crown of Hostas to prevent burning. Applying the fertilizer before the leaves unfurl is recommended.
For optimal Hosta growth, feed them consistently during the spring. Use a slow-release fertiliser and supplement with a liquid feed every week or two for a quick boost. Liquid feeds are effective but short-lived, lasting 24-48 hours.
So! What are N,P,K?
The three essential nutrients that significantly contribute to the growth and health of Hostas, as well as other plants, are:
Nitrogen (N): Encourages leaf growth and development, giving Hostas their lush, vibrant foliage.
Phosphorus (P): Promotes strong root development, ensuring the plants have a robust foundation.
Potassium (K): Supports overall plant health, increasing resistance to disease and stress.
Hostas also require trace minerals such as calcium, magnesium, and sulphur.
Fertiliser ..... Granules/powder or Liquid
The most used fertiliser types are granules and liquids. There is no right or wrong, they are two different products made for different circumstances.
Granular/powder fertilisers provide a slow-release feeding solution. These fertilisers are available in pellet or coarse powder forms that decompose gradually in the soil over several months. For those seeking to apply fertiliser as a top dressing to steadily release nutrients over the course of one or two months, a slow-release fertiliser is the appropriate choice.
Liquid fertilisers act quickly and begin working immediately, making them suitable for treating plants in need. If a plant requires immediate attention, a liquid fertiliser can provide rapid results, but its effects are short-term. Additionally, liquids are susceptible to being washed out of the soil by irrigation or rain.
Fertiliser spikes function similarly to granules, providing a slow release of nutrients. These small sticks or tablets of compressed fertiliser dissolve progressively with the presence of moisture. Additionally, they come pre-measured, reducing the risk of over-fertilisation in your garden.
Make sure to read the packaging so that you put the correct amount of spikes by or in your plants.
So! What are the Best Fertilisers for Hostas
There are so many fertilisers to choose from but I’ve managed to narrow it down to a few really solid fertilisers that are perfect for growing Hostas. Whether you prefer ground-planted or potted varieties, there’s something for everyone. Now you just have to decide what method you prefer.
Mulch
Consider applying a layer of organic mulch, such as shredded leaves or compost, around the Hostas after fertilising. Mulch helps to regulate soil temperature, retain moisture, and gradually release nutrients into the soil as it decomposes. If you have snail or slug problems in your garden avoid this step, as it may just encourage them to move in!
Proprietary Fertilisers
Any balanced fertiliser will do It will have NP&K at equal levels perhaps as 10:10:10, or 7:7:7, either liquid or granular.
Something like Miracle Grow comes in liquid or granular form, or Growmore normally as a granular fertiliser. Organic Seaweed is also good for your Hostas. Vitax Q4 is also on the market.
Here at the nursery, we tend to use a granular chicken manure. This is easily controllable and easy to apply, especially as we have a large number of containerised Hostas.
As long as they are balanced, it comes down to your preference and availability. The choice is yours. It's not as complicated as you might think.
Common Mistakes When Fertilising Hostas
Over-fertilising
Applying excessive amounts of fertiliser can cause Hostas to develop weak, leggy growth, making them more susceptible to pests and diseases. Over-fertilising may also lead to fertiliser burn, which damages the plant’s roots and turns the edges of the plant’s leaves brown and crispy. To prevent this issue, follow the recommended application rates on the fertiliser label and consider reducing it to 50% initially to observe how the plant responds. Additional fertiliser can be applied later if necessary.
Applying excessive fertiliser does not necessarily result in larger plants.
Nutrient Balance
Use an all-purpose balanced, slow-release fertiliser for optimal growth. Incorrect fertilisers can cause imbalances and poor health.
Avoid Foliage Contact & Water Thoroughly
After fertilising, water thoroughly to dissolve granules and distribute nutrients evenly. Lack of watering can lead to uneven distribution and root burn.
Timing Issues
It is important to apply fertiliser during the key growth periods in particular early spring through to late spring, and again if necessary, in early summer, and mid to late summer.
However, closely monitor your plants' conditions. If they appear to require nourishment, proceed to feed them; accordingly, if they do not, it may be prudent to refrain from doing so.
Fertilising Hosta in Pots or Containers
Growing Hostas is a great way to add texture and interest to your outdoor space and, since slugs love Hostas, it’s a great way to help keep them out of reach. Plus, if you don’t have a very big space, plants in pots might be your only option.
Bear in mind that Hostas grown in pots will need fertilising and watering more often, so a water-soluble fertiliser might be your friend here. It’s important to feed them at least once in the spring and again in mid-summer.
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John Plant
Rewela Hostas
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