Do Hostas like Wood Ash?

Do hostas like wood ash? Wood ash is typically recommended to hosta gardeners for its slug-repellent nature, while its impact on soil pH and nutritional value is overlooked.

Wood ash can be great for hostas growing in very acidic soil, as it increases the pH balance. Other benefits are added nutrients such as calcium, potassium, and magnesium. However, wood ashes should be used only in moderation and aren’t the best suited for pest control on hostas.

Let’s take a look into the components of wood ash, what it adds to hosta soil, and if wood ash is good for hostas.

Is Wood Ash Good for Hostas?

Like any other soil amendment, the effects of wood ash on your hostas will vary based on your soil type. If you’re unsure what makes up your soil, it’s best to do a soil test before making any big amendments.

Hostas like soil with a pH level between 6.5 and 7.5. If your soil is more acidic than this, your hostas may benefit from a layer of wood ash to increase the pH balance.

However, hostas in soil that’s already too alkaline would suffer from having wood ash dispersed in the soil, as it would then be even more unsuited to their needs.

Wood ash also includes minerals that are beneficial to hostas, such as calcium and potassium. To increase potassium in the soil, you can use up to 1.5 pounds of wood ash per 100 square feet

However, keep in mind that potassium level isn’t the only factor to consider. If your soil pH is at a good level, I don’t recommend adding wood ash simply for nutritional purposes.

Instead, you should purchase fertilizer or add other compost to make up for any deficiencies in the soil.

Ash left after burning wood

What does Wood Ash do to Soil?

When looking at wood ash and its benefits and detriments to hostas, I like to go back to its components and their effects on soil. Here’s a brief rundown:

  • Wood ash contains high concentrations of calcium carbonate, which makes the soil more alkaline (raises pH).
  • Silicon dioxide is found in some types of wood ash more than others. This is beneficial when growing crops, but inessential to hostas.
  • Trace amounts of potassium, magnesium, iron, and various other beneficial minerals are found in wood ash and would benefit your hostas if your soil were deficient in them.

It’s important to note that there’s little here that your hostas couldn’t get through other means. The main consideration when using wood ash should be its impact on soil pH.

Leopard slug on a green hosta leaf

Does Wood Ash for Hostas Deter Slugs?

Many gardeners recommend using wood ash to deter slugs and snails from hosta gardens, but is this an effective way to manage pests?

The problem with wood ash is that it only deters these critters when it’s dry. You would need to reapply wood ash to your hosta garden after every rain or watering for it to be an effective deterrent.

This seems like a pain for the average gardener, and would also be a detriment to your hosta’s soil as too much wood ash would increase the pH substantially over time.

Maybe this method would work in an arid environment with a plant like cacti, but hostas need consistent watering. Thus, this is a pretty ineffective method for keeping slugs and snails out of your garden bed.

Related Questions

How much ash should I put in my soil?

It’s best to use wood ash only in moderation. Add a thin layer to soils that you’d prefer to be less acidic.

Which plants like wood ashes?

Wood ashes are best for plants that like alkaline soil. When using wood ash as a garden amendment, however, it’s best to look at both the current soil pH and the plant’s pH preferences. Extremely acidic soils benefit from wood ash to make them more plant-friendly.

Closing Thoughts

Wood ash definitely has its place in hosta gardens, but like any tool, you need to know its use. I recommend it to balance out pH with an added nutritional benefit to your hostas. However, it shouldn’t be overused or depended upon for pest management.