Hostas are hardy plants that grow in many soils, but they do have preferences. What is the best soil for hostas? How can you amend yours to help your plants thrive?
Soil for hostas should be organic, freely-draining, and slightly acidic. They do well in a fertile mix that provides plenty of nutrients. Alongside this, they like soil that holds moisture without waterlogging their root systems. Many backyard soils will need to be amended to match these criteria.
Below, we’ll dig into what these requirements mean, and discuss how to amend your soil base or create your own mixture from scratch.
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Best Soil for Hostas
My personal favorite hosta soil is one we used in the nursery. It consisted of 10 parts Douglas fir bark, 1 part pumice (double screened) and 1 part coir or peat moss, along with some fertilizer and insecticide.
The mix changed slightly to include more peat for smaller pots.
This can be a pricey mix for home growers, but you can likely replicate this mix by replacing materials with those easily found in your area. There are, of course, many variations that will do the same job.
To break down the mix above, we used peat moss to hold moisture and provide nutrients and acidity to the soil. Pumice and fir bark provided an airy, well-draining quality to the mix, while the fir bark also worked to hold some access moisture for the plants.
Remember, the best soil mix for hostas:
- Drains well,
- Retains moisture,
- Is organic,
- And is slightly acidic.
If you keep these elements in mind, your hostas are sure to thrive in their new home.
Amendments to Poor Hosta Soil
Many gardeners don’t begin with the perfect soil in their backyards. Fortunately, you can make amendments depending upon what your soil currently looks like. Two common problems we see in hosta soils are poor drainage and lack of nutrients. The chart below shows materials you can mix in to solve these difficulties.
Pine or fir bark
When adding organic materials for the sake of providing nutrients to the plant, remember that they should be well broken down and decomposed. Large particles will remain in the soil and provide other benefits, such as bark that aids drainage and retains moisture.
However, they won’t provide any nutrients for your hostas until they decompose, which in some cases may take years to occur.
If you prefer not to amend your soil, consider growing hostas in containers or creating a raised garden bed for your new plants. Sometimes, starting from scratch is the easiest way to create the best soil conditions for hostas.
Hosta Soil pH
Do hostas like acidic soil? The answer is yes, so long as it isn’t too acidic.
The best soil pH for hostas between 6.5 and 7.5. They prefer soils that are closer to neutral, but will grow fine in acidic and alkaline soils as well.
Remember that with soil pH, readings over 7 are alkaline, and readings under 7 are acidic.
If your soil has a much higher or lower pH level than listed above, consider amending it before planting.
To raise soil pH, add limestone to your soil. Limestone is sold in varying sizes. The smaller limestone affects pH level the fastest, as it breaks down more quickly, while bigger chunks will be more affective over longer periods.
To lower soil pH, try aluminum sulfate for an immediate effect, or sulfur for a slower release over time.
Will Hostas Grow in Clay Soil?
Some growers recommend hostas as a plant that will grow in clay soil, but is this actually true?
While hostas can survive in clay soil, they don’t thrive in it. You’ll likely need to amend this type of soil with organic material if you want healthy, full plants.
It’s difficult for roots to grow through hard clay soils, so you’ll want to choose additives that make the soil looser and airier. This will also provide drainage so that your hostas don’t become waterlogged.
In addition, you’ll want to provide nutrients to help your plants flourish.
Downsides to planting hostas in clay soils include:
- Nutrient deficiencies
- Poor root system
- Root rot
You can also choose to build up from your clay soil using a well-draining, organic, and slightly acidic mixture, or to plant your hostas in pots instead of the ground.
The major benefit to this is that it tends to be less work than digging into hard clay soil to mix in other materials. It can be as easy as finding a good potting mix and pouring it in.
Beware of growing hostas in pots in cold climates, though, as you’ll need somewhere to overwinter them if you’d like them to survive into the following years.
Can Hostas Grow in Sandy Soil?
Unlike with clay soil, hosta roots can easily move through clay. Your plant might do okay in this soil type for a while, but it may begin to suffer if you treat your sandy soil like a rich garden soil.
Sandy soil tends to be nutrient-deficient. Like clay soils, they’ll need organic materials mixed in if you want your hostas to grow healthily.
This soil type also drains too quickly for hostas, so additives that help retain moisture are a must.
Downsides that hostas can face due to sandy soil include:
- Nutrient deficiencies
- Poor hydration
- Increased risk of sunburn due to lack of water intake
On the bright side, I’ve found that sandy soil is much easier to amend than clay soil since it’s much lighter and looser. It just takes a little work on your part before you plant your hostas.
I’d suggest you give it a try! Mix in peat moss, compost, coir, composted manure, mulch, or leaf mold before you plant your hostas. It’ll give the soil a nutrient boost and help it retain water.
For more information on growing hostas in sandy soil check out our detailed article, Will Hostas Grow in Sandy Soil.
Best Soil for Hostas in Pots
Hostas grown in pots will need a different mix than those grown in the ground. The most important thing to know is that you should look for potting soil, not garden soil.
The reason for this is that potted plants have different needs, and have a much smaller area to grow within.
Potting soil will create a better balance between moisture and drainage for your container plants, and your hostas will be healthier for it.
When choosing a potting soil, look for a light, fluffy mixture that doesn’t compact when watered. It should be very easy to dig into with your hands, and water shouldn’t pool at the top of the mix for more than a few seconds.
You might consider adding in slow release fertilizer to your soil base, as this will keep your hostas nourished. The alternative is to apply fertilizer regularly to your potted plants, as they will use up the nutrients in the soil quickly.
Is Miracle Grow good for hostas?
Miracle Grow is a decent, cheap gardening solution. So long as you choose a mixture that’s formulated for your hosta’s specific needs (a potting soil for potted hostas, for example), it will work just fine. However, there are better soils on the market if you don’t mind spending a little extra.
Do hostas like coffee grounds?
Coffee grounds provide nitrogen to plants and can be good for nitrogen-deficient hostas or soil mixtures. However, they aren’t needed for healthy plants and also shouldn’t be used in excess in your garden. Our article on hostas and coffee grounds contains some of the latest research available.
All in all, hostas are incredibly hardy plants that will survive in a variety of soil types. However, the above advice will give you better than okay hostas—it will help your hostas to truly thrive in their environment.
Provide your hostas with all that they need, and they’ll reward you with a beautiful garden for years to come.