Planting * Spacing * Fertilizing * Watering * Digging and Dividing * Mulching * Grooming * Hybridizing * Foliage Types * Seasons * Pests and Disease

Hostas are low maintenance garden perennials. They do very well in our northern garden, but apparently hostas do not grow well everywhere. Garden acquaintances have told me that many hostas do not grow well in the southern states as they do not like the intense heat. In our climate they can survive an amazing amount of neglect and still grow for years. But if you want your plants to be the best they can be, we recommend that you give them the best start possible. This care begins when you receive your new plants.

It is recommended that if planting in the spring of the year in the colder climates, you wait until the soil warms to above 50df. If you can comfortably walk barefoot in the garden, it is about right. In the north, you can plant almost anytime during the summer, as we generally do not experience intense heat. If planting in the fall, you want to be at least 6-8 weeks before the ground freezes so that the plant has time for the roots to establish themselves.

If you purchase your plants "bare root", the first thing that you should do is to unwrap them from whatever packing material they arrived in, and put them to soak for a few hours to rehydrate the root systems. Do not be overly alarmed if they appear a little limp or even a little yellow upon arrival. Sometimes in transit they do get stressed a bit, but generally they rejuvenate well once rehydrated and planted. When people soak their plants, they can use a variety of solutions. Many use straight water, while some add a weak solution of fungicide, Clorox, or even liquid fertilizer. There are mixed reports of which works the best, it seems to be merely a matter of which appeals to you. If you do add something to the water, it is important that it be a weak solution so don't overdue it. As long as the plants are in a cool and shady area, they can remain in this soak for several hours optimally, up to several days. Optimally they should be planted within 24 hours.
If it isn't possible, and they remain in the water for an extended period, it should be changed frequently so that bacterial growth doesn't occur. If we are not going to be able to plant newly arrived cultivars in a timely manner, we generally pot them until we will be able to set them out into the gardens.

When you plant the cultivar, the better amended the soil, the better your plant will respond and the better the blooms there will be in the years to come. There are many ways to prepare the garden site and plant hosta. Hostas are considered to be "shade" plants, but in actuality they are shade tolerant plants which also grow well in less shady areas. We actually grow many hostas in the full sun and they not only survive, but multiply much more rapidly than in the shady sites. The one thing that is quite noticeable however is that much of the time in full sun you will not see the more subtle leave colorations or patterns. It isn't until they are in a less sunny environment that those characteristics become more evident. Some hostas will actually get scorched and show some browning around the leaf edges when grown in the full sun, but this doesn't seem to impact their growth rate. Hostas grow best in a rich humus soil. Clay soil will benefit from adding compost, peat moss, sand, or other organic materials which will improve its drainage. Sandy soil can be improved by adding compost, peat moss, and other organic materials, which will help it to retain moisture. Hostas prefer well drained soil. The biggest challenge we have had with planting our hostas in shady areas is that they are constantly competing with tree roots. Some trees are more of a problem than others, depending if they are ones with deep or shallow root systems. Most of our shade is provided by large and very old Maple trees. These are not the best choice for an under planting of Hostas as they have shallow surface roots and sometimes it is difficult to find a space where you can dig a hole large enough to plant your hostas. (It is very important to not change the soil level overly much by bringing in new soil and planting on top of the roots, as this can actually suffocate the trees which need their roots to be near the surface.) Our solution has been to plant the hostas where ever we can dig a large enough hole, and to plant other shade loving perennials which don't need as much soil (such as Epimediums, Huechera, and Sweet Woodruff) between them. The other major concern for the plantings under large trees is the competition for water. We combat this by frequent watering.

Once you have decided on the site, dig a hole larger than the amount of roots to be planted. The hole should be at least a foot deep. Remove the loosened soil from the hole. Mix your compost or other organic material into the loosened soil. Put a shovel full of aged manure or compost in the bottom of the hole and spread it evenly. Put about ½ of your soil mixture into the hole. Make a cone of this soil in the center of the hole. Place the hosta on the cone with its roots draping down into the hole. Now fill the hole with the remaining soil, tamping it in around the roots to eliminate air pockets. The crown of the plant (which is where the foliage meets the roots), should be ½ to 1 inch below the soil when done. Water the newly planted hosta well. We make a little collar of soil around the outside edge of the hole so that when we water, it will collect within the collared area and soak into the ground rather than running away. We rarely get any leaves which brown or die back. We would suggest that any with a large amount of tall foliage should be supported until the roots have time to establish themselves. We generally stake them. A top layer of 2-3 inches of mulch around the plant will help retain moisture and retard weed growth. Do leave 1-2" space free of mulch where the plant emerges from the ground.

If you purchase your plants potted, they can be planted with very little disturbance. They can remain in the pot for an extended time, or be planted immediately. As long as they receive adequate water and fertilizer, they can remain in the pot for months. When you are ready to plant them, just remove them from the pot and if the roots are showing spiral growth just fan them out or cut them (if needed) before putting them into your prepared hole. In this instance you don't need to prepare the cone of soil in the middle of the hole, just put the plant into the hole and fill with the remaining dirt. Any extra soil can just be smoothed out over the surface.

Hosta are generally considered to be slow growing plants which can take up to 5-7 years to reach mature clump size. Knowing this it can be very tempting to plant them closer together than would be prudent. Hostas also come in a huge range of sizes, from miniatures that only grow to be 2 inches tall and 4 inches wide to the giants which can be nearly 4 feet tall and 7 feet wide! It is really very important to take the size of the mature clump into consideration when planting. You wouldn't want to interplant a mini with a giant! The minis generally look the best, in my opinion, when grouped together in a very visible spot such as near a seating area or near the edge of a walking path, otherwise it is very easy to totally overlook them. With that said, most hostas of varying size can be successfully interplanted. If you want your garden to look fuller sooner, go ahead and plant them closer together, but know you will have to go back in a year or two and remove some (alternating ones?) to avoid overcrowding. Be prepared for this transplanting to be a bit more of a project than when they were originally planted, because the roots of a happy hosta can get quite large and heavy. Alternatively, you can plant your hosta with more space initially to allow for mature size, and to make the garden appear to be more filled in, plant other shade loving annuals and perennials amongst the immature hosta plants.

It is recommended that you not fertilize your hosta the first year after planting. They get their nutrition from the amendments added initially to the soil in which you planted them. After that first year, hosta are generally fertilized in early spring when they begin to emerge. Do be careful when putting on the fertilizer that you do not get it on the crown itself, but around the crown. Fertilizer on the crown can severely set it back or kill the hosta! There are many fertilizers that are used, but we normally use 10-10-10 as our general all purpose fertilizer. If you prefer an organic fertilizer there are other options, side dressing or mulching with compost works well.

Hosta prefer at least 1 inch of rain a week. As with most garden plants, they will grow more quickly and look more beautiful if they receive adequate moisture. We recommend early morning watering versus mid-day or evening watering, which is good gardening practice regardless of which plants you are growing.

Digging & Dividing:
As your hosta grow and multiply they make what is referred to as a clump. While many people divide their hosta frequently to share or to spread to additional spots around their property, some say that a hosta never needs to be divided. If you do decide you wish to divide your clump of hosta, you can either dig up the entire clump and then cut it into separate portions, or you can just cut out a piece of the clump while leaving the majority of the clump undisturbed. Hosta roots are not known for being easily divided, and you will need a knife or even a hatchet or shovel to divide. When dividing it is important to be certain that you have both top (foliage) and root for each piece removed from the clump. (Sometimes if all the foliage comes off but there is viable crown on the root, the plant will still survive, but it will take a significantly longer to grow.) You can divide your clump into several small clumps, or even into individual fans. The more you divide it the more small plants you will have, but each smaller plant will take longer to get established and increase. It is recommended that you allow any cut surfaces of the roots to dry prior to replanting. Some people like to put fungicide on the cut surfaces to discourage disease.

Mulching your hosta helps to maintain the soil temperature, retain moisture, and retard weed growth. In northern regions, mulching can also help protect the plant from extreme winter temperatures. A 2-3" layer of mulch is sufficient to accomplish this. When putting on the mulch, do not apply it right up to the base of the plant. Most plants need a small zone around where they emerge from the ground to be free of mulch. Depending on the area you live in, there are many different mulching materials available.

There may be times when you wish to make your hosta look their very neatest. In our garden, we generally do not groom unless we are expecting a large group in to view the gardens. By grooming I am referring to the practice of "deadheading", "liveheading", and "trimming". To "deadhead" your plants, you snip off the "spent" or old blooms. To "livehead" you remove the current day's (or future) blooms before they are spent. Many people do not find hosta flowers to be attractive, and they routinely remove the flower stalks before they bloom. This doesn't harm the plant in any way that I am aware of, and it does eliminate the possibility of stray seedlings coming up in the garden.

NOTE: Do not remove blooms if you are intending to allow seeds to develop! Removing the blooms normally removes the future pods! Yes, if you are very careful you can remove the spent bloom without removing the developing ovum, but it generally isn't worth the risk.

Trimming is done in our garden only rarely. We would trim a leaf or two if we had a plant in a prominent garden location whose foliage was unsightly. Perhaps it got hit by the weed whacker, had hail damage, was burned by fertilizer or had particularly bad slug damage. We could simply cut back or trim off a very few of the most effected leaves that were ragged or discolored.

Hybridizing is the making of seeds by crossing different cultivars. In nature the bees and other insects or even wind can accomplish this. Many growers, in the quest to develop new types of hostas have done the crossing of the plants themselves rather than leaving it to nature. To do this one only has to take the pollen form one plant or bloom and put it onto the pistil of another plant or bloom. The pollen is from what is called the pollen parent. The plant receiving the pollen and that develops the seed pod is called the pod parent. After the bloom is pollinated, generally seeds develop in a pod, and then over the summer the pod ripens. The pod is harvested once it is ripe and the seeds are gathered and later planted. These seeds will become new plants, which have traits from both its pollen and pod parents. If when these new plants grow and bloom they show improvement over the parent plants and other plants in commerce, the hybridizer may decide to introduce and register the plant. If the plant has no redeeming qualities, it is frequently composted.

Foliage Types:
There are basically 2 types of hosta foliage, variegated and non-variegated. If variegated, it can be either edge or medially variegated. So if it is light in the center part of the leaves it is "medio" variegated and if it has a light area on the edge of the leaves, it is said to be "marginally" variegated. There are also some new "unusual" foliage looks that are being seen in today's marketplace and gardens. It is possible to see leaves which appear to be streaked, stippled, misted, and even puckered. In addition to all of this, hosta foliage can range in color from almost black, deep dark blue grey to green to pale yellow. Many hostas emerge in the spring as one color but actually develop into another darker or lighter color as the season progresses. Some hostas may have darker or red coloration on the stems or petioles which make them unique. With the range of possible colors and then the addition of variegation there are many combinations resulting in some very unique looking hosta.

Although most gardeners don't think of hosta as a flowering plant, modern hostas can be seen blooming from early spring to late fall. This has been accomplished by breeding the plants with different or extended bloom seasons. They are classified as early, midseason, and late. Most hosta flowers range from white to purple, with some of them being stripped in appearance. Generally speaking the hosta blooms have not been considered to be an attractive feature of the plant, and many growers routinely cut off the flower scapes as they begin to develop rather than have them visible in their gardens. This may change, as some hybridizers are working on developing blooms that are more attractive. Some now can be seen that grow uniformly around the scape rather than being all on one side, are doubled, or even spidery in appearance. Hostas (which were once only considered for their foliage contribution in the garden landscape), may soon be viewed equally for their attractive blooms.

Pests and Disease:
Pests that may affect hosta in our area are snails, slugs, and as few larger "pests" such as voles, deer, and other grazing animals. There are products and home remedies available to use to deter the above mentioned pests if you have a problem. Be sure that whatever you use is safe for hostas. Your local garden representatives such as your extension service or farm store can recommend the right product for you.

Foliar nematodes can cause severe damage to hosta. (We have not seen evidence of nematodes in our garden, but it is always possible when purchasing plants to inadvertantly bring new pests, disease, or even weed seed to your garden.) These nematodes were originally imported on contaminated plants. They are spread by splashing water, and they can over winter in the crowns of hosta. Foliar nematodes feed on the leaves between the veins, and this can cause the leaves to brown (but not generally noticeable until mid to late summer). If you have a nematode infestation, the lifecycle can be interrupted by soaking the affected plants in 120°F water for several minutes. After their soaking, pot the plants up and grow them in isolation for at least 6 months to be sure they are nematode free. Your local extension office should be able to give you information to help you.

Leaf Spot and Petiole Rot may also be seen in the hosta garden. The spotting can be caused by a cool damp spring. Fungus can also cause spotting in addition to the petiole rot which has been seen in southern gardens where it is hot and humid.

Viral infections can be a problem for hosta growers. Hosta which are in poor health are more prone to a viral infection than are healthy plants. If infected, a plant can be isolated, treated, or if unavoidable, destroyed to prevent further spread of the virus. The most effective way to protect your plants from a viral infection is to be preventive. The spread of virus is significantly diminished if when dividing hosta you dip the knife into a bleach or alcohol solution before and after making a cut. The most common viruses that effect hosta are tobacco rattle virus and tomato ring spot virus, although the Arabic mosaic virus is also possible. An infected plant will have chlorotic spotting and stunting or deformed leaves. Most often, these same characteristics are seen due to drought damage and not due to a viral infection.

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