Hosta Care and Maintenance, Growing Tips

Basic Hosta Care and Maintenance, including Growing Cycle, Watering & Fertilizing, Weeding, Mulching, and Blooms.

Hosta Growing Cycle

In Minnesota, the shoots begin to emerge from the soil about the 2nd week of April until the 2nd week of May (depending upon the specific cultivar, plant location, and weather) and elongate and unfurl into leaves.

To promote an early hosta growing cycle a balanced 20-20-20 or 10-10-10 fertilizer could be applied just before the hostas emerge. The next growth spurt takes place in the roots in early to mid-June, when you can apply a second dose of fertilizer, with lower nitrogen content but with higher phosphorus and potassium content.

Trees

The type and size of trees is important hosta garden information which needs to be taken into account to get the most out of your hostas. Shallowly rooted trees not conducive to hostas include: beeches, birches, cherries, maples, and willows. Trees producing excessive suckers include cherries and poplars. Trees that can be good for nearby hostas include oaks, some hard maples, lindens, hickories, elms, pines, spruces, ash, larch and dogwoods. Although walnut trees are not compatible with some plants, they are compatible with hostas.

Moss

Moss grows in wet, often shaded, acidic soil. Rather than using expensive moss killers, try removing the existing moss with a shovel and disposing of it. Then use lime to slightly change the pH of the soil and the moss will disappear. However, remember that hostas like acidic soil.

Erosion control

Most hostas are clump-forming herbaceous perennials that have a rhizome (an underground storage organ). In a few hosta varieties, the rhizome is stoloniferous, meaning it grows horizontally and produces new plantlets along its length. These hostas are particularly useful for ground cover, slopes and erosion control. Since they grow tightly, you do not ever need to divide them to create new plants.

Watering

Water-related hosta maintenance is minimal if you live in reasonably moist area. Hostas prefer about 1 inch of water per week, depending on the plant, location, temperature and soil.

In most soil types, 1 inch of water will soak down about 12 inches. In loose, sandy soil, water will soak down more quickly.  Ideally, water should  be applied to the base of the plant (not the leaves).

Hostas should be watered in the early morning so that the leaves dry off before the intense afternoon sun comes out. Water on the leaves increases the sun’s effects. Morning watering also reduces the attraction for slugs and snails.

Make sure there is adequate soil moisture, in particular during the hot months of July and August. New plantings and slow-growing hostas are most vulnerable to moisture fluctuations, including sieboldiana and tokudamas.

If the root system dries out at an early growth stage, the plants seem to shrink in size over time. As a regular part of your hosta maintenance, be sure not to let your gardens become completely dry for longer than a week.

Watch as Tom Carlson demonstrates several hosta watering methods and explains how trees and shade can affect your hosta watering amounts.

Fertilizing Hostas

fertilizing hostas Hosta 'Blue Mouse Ears' from HostasDirect.com
H. ‘Blue Mouse Ears’

In mature hostas, forgetting to feed will not make a huge difference. How much to fertilize your hostas depends on your garden situation, because healthy plants need a balance of light, water, nutrients and the proper soil.

Hostas that are constantly moist may require more nitrogen as nitrogen will leech (wash out) of the soil. Sandy soils will leach nutrients faster than more clay or humus soils.

If your garden is in deep, dark shade, more fertilizer might not be the solution to increase the plant size or growth rate because the problem is insufficient light.  Excess fertilizer in this circumstance could burn or stunt your plants!

Overall, fertilizing can provide hostas with a boost if they are in nutrient-poor soil.

Fertilizing Tips and Tricks

Tom Carlson’s fertilizing video explains some of the best hosta fertilizer hardware and how to use it. See the hosta videos page for more HostasDirect Productions.

Fertilizer Types

Fertilizers come in liquid feed, granular and slow-release. Liquid hosta fertilizer is ordinary garden fertilizer such as Peters, Shultz or Miracle Grow that can be drenched into the soil or sprayed on the leaves as a foliar spray. Drenching the soil is more effective but is harder to do after the hostas unfurl. Standard 10-10-10 inorganic garden fertilizers are quite inexpensive.  However, the nitrogen can leach out of the soil fast depending on the amount of water applied and soil type.

Do not let granular fertilizers remain on hosta leaves as they can burn small holes in the leaves.

In Minnesota, using a time and temperature released fertilizer may create problems. Some types of hosta fertilizer require a temperature of 70 to 77 F to start releasing fertilizer into the soil and will release fertilizer for 60, 90 or more days, which releases fertilizer in August.  It is important not to fertilize hostas past late-July, as the plants should not be over-stimulated to make new growth.  This can be harmful, since fertilizing hostas after July 31 may promote soft, sappy growth that slugs and snails will appreciate. Hostas need to slow down in the fall and harden off for winter.

High nitrogen fertilizers that are often used for lawns such as 30-0-5 can produce tremendous growth, but may make the plants more susceptible to various fungal and bacterial rot. Osmocote has many different time release products that are excellent.

Foliar Feeding

Foliar hosta fertilizers are liquid fertilizers which are absorbed through the leaves and roots. Foliar fertilizer needs to be applied every two to three weeks during the growing season if not weekly since it remains in the root zone for shorter periods of time than soil-fed fertilizers.

Soil Feeding

Hosta 'Fire Island' from HostasDirect.com
H. ‘Fire Island’

These fertilizers are absorbed through the soil.

Organic fertilizers have lower analysis numbers than inorganic fertilizers and, therefore, tend to burn less. However, you will need to apply them more frequently to get the same amount of nutrients. They may also attract voles.

Manure

BE CAREFUL! Some manure is full of weed seed that will create extra weeding for you. Make sure the manure is well-rotted so it does not burn the plants as it decomposes, and also free of weed seed. This is tough to guarantee. If you do find good manure, it can really make your hostas grow with low maintenance as it breaks down, naturally fertilizing hostas for years.

Weeding

Kill all weeds before planting.  We like Roundup and recommend our premium garden weeding tool to quickly pull weed roots out of the soil. Be sure to continue to weed frequently in order to eliminate weeds from ever going to seed. If you do this, you will find your hostas will keep out most weeds because they create so much shade and your garden will be low-maintenance, look beautiful and be much less work than grass. Again, do not let weeds go to seed!

Weed Killers

Some gardeners use Preen in the spring. Preen is a granulated, pre-emergent weed killer which is compatible with hostas. Some use Round Up, which will kill anything green, so it is wise to be careful with it. Some gardeners use a combination of both.

Mulching

Hosta 'Ann Kulpa' from HostasDirect.com
H. ‘Ann Kulpa’

There are pros and cons to mulching hostas. The benefits to mulching as a form of hosta maintenance include: controlling weeds, keeping soil cool and moist, and adding compost as the mulch breaks down. (Wood chips and green grass clippings can deplete nitrogen from the soil as they decay.) On the downside, mulching provides hiding places and food for pests and diseases such as slugs and viruses.

After much thought and study, HostasDirect does not apply mulch except to cover new plantings in late fall. This is because newly planted, very young, or prized plants should be covered or mulched with oak leaves or straw for the winter. Mulches should not be applied before the ground is nearly frozen in the fall, and it should be left in place several weeks after the ground thaws in the spring since it will prevent alternating freezing and thawing, which can cause plants to heave out of the ground. Do not use freshly cut grass as mulch; allow it to turn completely brown before using it as mulch.

Blooms

By cutting off your hosta’s blooms, you will provide more energy to the plant that would otherwise be used to make seeds. You do not need to cut the blooms off until after they fade, but they can be cut off at anytime. However, leaving your blooms on is helpful to the declining honey bee population.