If you've heard that hostas can grow in any soil type, even poor soil, that's not exactly true. While established hostas tend to become comfortable in any soil over time, they certainly won't thrive and retain the beautiful leaves that you grow them for. Young hostas planted in poor soil will eventually succumb to disease and die.
If you want your hostas to thrive, the key is soil that is rich. The ideal soil pH for hostas ranges from 6.5 to 7.5, which actually means it's slightly acidic to slightly alkaline.
Soil for a new hosta bed
For a new hosta bed, till in about six inches of organic matter. This can include leaf mold, compost, well-rotted manture, peat moss or composted pine bark. These amendments will do wonders for giving young hostas the nutrients they need to develop good, healthy roots and also will provide air space for rapid root growth.
If the soil has a great deal of clay, it is best that you improve the soil. You can add some coarse sand or small gravel or pebbles which will also help with good drainage.
Dig the planting hole at least a foot deep. And since most hosta roots spread horizontally, a width of one and a half times the mature size of the clump is recommended.
For a detailed article on composting, click here.
For a detailed article on making leaf mold, click here.
Roots of young hostas can tend to heave up above ground over the winter. Do a quick spring check of this and bury the exposed roots.
Refreshing the soil in a previous hosta garden
If you are lucky enough to have loamy soil in your garden, which is pretty rare, you may not need to add anything other than a few inches of organic matter each Fall. This practice will also slowly raise the bed, improving the soil's ability to get the water down to the roots.
If your soil is in very poor shape, you may want to actually lift the hostas out, add your nutrients and replant.
Refreshing the soil in hosta planters
Hostas in planters or pots need soil that has good air circulation to the roots and good drainage. Some of the ingredients in commercial potting soil will break down over the years causing the mix to compress and lose some drainage capabilities.
Adding Perlite, bark, grit, pebbles or the like will help to aerate the soil again. An addition of sphagnum peat moss or coir peat will help hold in the moisture that hostas love.
For a detailed article on refreshing and reusing last year's potting soil, click here.
Check the drainage holes in your containers or pots each spring and make sure they aren't clogged.
Hostas love and need lots of water. A minimum of an inch of water per week, either from irrigation or rain, is recommended. However, roots that set in stagnant water will rot and eventually kill the plant.
Fertilizing your hostas
Hostas will get a great seasonal boost if you fertilize them every spring before the first shoots appear. Granular fertilizers of 5-10-5 or a balanced fertilizer of 10-10-10 will do the trick.
Healthy soil and a dash of spring fertilizer will reward you with those beautiful leaves that we grow hostas for.
So although hostas are known for their toughness, if you allow them to grow in great soil, they will reward you with their beautiful leaves for many years.
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