The Hosta Gardening Calendar

by Bob Solberg

Winter (Period of dormancy): December-January-February-March

In winter, hostas are dormant, they do not grow at all. There is no winter root growth as in other perennials. Most hostas need 600-700 hours below 40 degrees F of cold dormancy, but they will emerge as stronger plants if their dormancy is extended beyond the minimum required.

Hosta 'Sun Power' Labeling: Make new permanent labels.

Light: Full sun, under deciduous trees, but very weak intensity.

Nutrients: None needed

Pests: Check for fresh vole runs, especially after the snow melts. Bait runs or set traps as necessary.

Protection: If the garden was not mulched in fall, this is an easy time to touch up that 1” layer of coarse mulch.

Propagation: None.

Water: Usually no extra watering is needed. In very dry winters, especially in areas that usually do not have snow, watering once or twice throughout the winter may be needed or emergence of the foliage may be delayed and the plants will be smaller.

Fun! Surf the Internet for hosta information. Make want lists of new hostas from hosta catalogues received in the mail and on your favorite websites. Many nurseries have “Early Bird” specials in January. Catch up on reading The Hosta Journal. Visit

Spring (Foliage emergence begins): March-April-early May

hosta eyes emerging As the ground warms under spring’s ever increasing light intensities, the dormant buds of the hostas begin to swell and break through the mulch, looking like bullets coming out of the ground. The small bud scales that protect the true leaves open and recurve allowing a cigar-shaped flush of usually three to four leaves to emerge well above the ground. Soil temperature and moisture seem to effect the timing of the emergence of hostas the most. In very dry winters the emergence of hostas will be delayed unless the garden is irrigated. As the new hosta leaves expand, ample water is also needed for them to gain maximum size.

Labeling: Check for lost labels and replace as needed.

Light: Full sun, moderate intensity. Usually no shading necessary.

Nutrients: Apply slow release fertilizer (e.g. Osmocote, Nutricote, organic fertilizers) or 10-10-10 granular fertilizer around clumps as the hostas emerge. If you only use a liquid fertilizer, then apply weekly beginning as the first leaves start to unfurl.

Pests: Begin slug control before hosta leaves emerge. The slugs will be active on warm nights before the hostas will. Try to limit their populations before they hide in the hosta foliage. If early attacks by deer are a problem, spray a repellent. Little is needed at this time but it may need to be repeated every 10 days as the hostas enlarge. Stay on vole patrol.

Protection: Finish your spring clean-up of fallen branches, old hosta foliage and scapes. Last chance to mulch. Pull mulch away from emerging hosta shoots to reduce the risk of petiole rot, especially if hardwood bark is used as mulch. Protect from late freezes with frost cloth, nursery pots, boxes, lightweight bed sheets or newspaper. Hostas with unfurled leaves can be protected by covering with mulch.

dividing hosta Propagation: Hostas may be divided in half or quarters as they begin to emerge. Be prepared to provide them with extra water and care as they will have oversized leaves for their recently reduced root system. New roots will not begin forming until the first set of new leaves are almost fully expanded, several weeks after division. Save drastic division for late summer.

Water: Keep the soil evenly moist. Fresh hostas are mostly water, make sure plenty is available as they expand. Beautiful spring days with bright light, low humidity and brisk winds dehydrate new hosta leaves quickly, do not be afraid to irrigate generously.

Fun! This is the best hosta season of the year! Go out several times a day and watch your hostas spring from the earth. You can almost see them grow! Count the number of new shoots and calculate how much your hosta investment has increased. A one division hosta purchased for $25 last fall, with its three new shoots, has now tripled in value to $75. Drag you neighbors over to see your hostas do their magic act. This is the time of year when everything is right in the hosta world. Go to a local hosta meeting.

Late Spring (Period of rapid foliage and root growth): May-June

Most hostas, except the fragrant flowered ones which produce new flushes of leaves into July, produce all their leaves in about 6-8 weeks. This occurs in usually one or two flushes of 3-4 leaves per shoot, (division). These leaves are at first “soft”, expanding rapidly, metabolizing, (growing) at a high rate. As they reach their mature size they “harden off” and stop expanding, slowing their production of white wax and purple pigments, (anthocyanins). At this time fresh new white roots emerge from the shoot above last year’s roots and lengthen rapidly. Soon the second flush of 3-4 leaves will appear and mature, followed by another period of root initiation. Hostas need abundant water and nutrients, especially nitrogen, during this period of rapid leaf and root growth.

Labeling: Pull labels further out from under the expanding hosta clumps. Notice how much bigger your hostas are than they were last year. Congratulate yourself and give your hostas praise.

Light: Shade fills the garden as the trees leaf out. Watch for bleaching of early rising yellow hostas. They may need to be moved.

Nutrients: Reapply 10-10-10 after 4-6 weeks depending on the amount of heavy rainfall. Continue your liquid feed program. If you want your hostas to be the biggest on your block, (and who doesn’t?), supplement granular fertilizers with a foliar liquid feed of a high nitrogen fertilizer with added magnesium every two weeks (e.g. Miracle-Gro Tomato Plant Food 18-18-21, Peters 20-20-20 with a pinch of Epsom salts per gallon of water added.)

Hosta 'Sum and Substance' infected with Hosta Virus X Pests: Check hostas for evidence of Hosta Virus X. Unlike foliar nematodes, HVX symptoms will show early in the growing season. Remove and dispose of any infected plants!!! Watch for slug and vole damage. If a hosta does not come up, go digging around looking for it. It may have become vole food, so check the hostas around it for vole damage by pulling gently on the foliage and seeing if they are firmly rooted in the ground. If they too have been nibbled, you may need to pot them up and regrow their roots. Bait or set traps. If a hosta comes up much smaller than last year, it may have become a victim of tree roots and need to be potted also. Remove all the rotted roots and soft parts of the crown and rinse it in a 10% bleach solution before potting. Make a note, that hosta bed may need reworking in late summer. Ugh!

Protection: Deter deer!

Propagation: Do not divide hostas with soft foliage. Once they harden off, you can move entire clumps safely, being careful not to damage the roots. Use a digging fork, not a shovel if you can so you do not cut off the root tips. Wait until late summer to divide drastically.

Water: Water, Water, Water! Especially if it is a dry spring. Fill your hostas to the brim with water.

Fun! Plant those hostas that you ordered in the winter. Happiness is a new hosta bed! Visit local nurseries and raid the big box stores; hunt for bargains and maybe do a little hosta sport fishing with your hosta buddy. Take pride in your perfect hostas, all fresh and free from holes. Show them off. Visit them daily and choose your favorites.

Summer (Period of bloom and seed set) June-July-August

The time of bloom in hosta species and their cultivars varies from late May or June to September. A particular hosta will normally bloom once for about 3 weeks during the summer, producing a flower scape from the growing bud that just finished producing the flushes of leaves. The scape has a number of lily-like flowers that are open for one day only and are bee pollinated. (H. plantaginea opens in the evening and may be moth pollinated.) Seed pods are formed from fertilized ovaries at the base of the pistil and swell in size. Black, single-winged seeds are usually ripe in 6-8 weeks.

Labeling: Replace the labels that the squirrels have pulled up.

Light: This is the brightest and more importantly, hottest light of the year. The sun is at its maximum height in the sky and often beds that were bathed in shade in early May are now in full sun. Hostas can tolerate direct light but they hate heat! If leaf margins begin to brown, it may be time to move that hosta to a cooler spot in the garden. On the other hand, year by year shade gardens become shadier. Consider removing a branch here or there during the summer to create spotlights of bright light in the garden. Maybe even consider removing an entire tree, but that should probably wait until winter.

hosta bloom scape Nutrients: Blooming hostas still need nutrients to maintain their foliage and produce seeds but not a high nitrogen diet. If you are liquid feeding weekly, continue if there is ample rain. In times of drought reduce feeding to every other week. Discontinue any supplemental foliar feeding; hosta leaves have expanded to their maximum by now. Remember if it doesn’t rain, then your slow release fertilizer is not being released. Irrigation may be a good idea.

Pests: If it turns dry, the deer will show up looking for some lush hosta foliage full of water. Spray deer repellent every 3 weeks or more often and rotate your favorite brands. Leave the electric fence on at all times. Be on the look out for the symptoms of foliar nematodes, those nasty brown streaks. If you have a major problem, remove the most highly infected hostas and water less and feed less. Starve the hostas and stress the worms. Quarantine your garden. If you have a minor issue, remove infected hostas and all the ones touching them. A few years of this may eliminate the problem almost completely.

Protection: Watch for petiole rot. This fungus attacks the base of hosta petioles, secreting a substance that eats through the plant tissue causing the leaves to fall on the ground. This usually occurs in the first hot dry weather of the summer. Pull back mulch. Treat with 10% bleach solution immediately and retreat if necessary. There are also fungicides (e.g. Terrachlor) that can be applied. Other fungi may attack the hosta leaves, especially in hot, humid climates in wet summers. Apply fungicides (e.g. Daconil) as a preventative in late June every 2 weeks as necessary. Rotate fungicides.

Propagation: Divide hostas as the heat of summer passes. August is the best time to drastically divide and plant or pot hostas. Try to give your hostas 6 weeks before the first frost to establish new roots in their new home.

Water: Like nutrients, a hosta’s demands for water are reduced after their leaves are mature. Increased temperatures however, increase the transpiration rate, the rate at which the water is pulled out of the hosta leaves, requiring more water to replace it. Transpiration affects trees to an even greater degree as they pump water up and out of the garden soil. In hot weather sometimes keeping your hostas full of water all day long is a constant battle. Continue the fight. Dry soil may cause your hostas to go heat dormant or worse, dry rot at the bottom of the crown. In heavily shaded gardens, irrigation during the day can cool those hot leaves.

Fun! Cut some scapes after a couple of flowers have opened and bring them inside to enjoy for two or more weeks. Cut and remove the other scapes when 75% of the flowers have opened, unless you wish to save the seeds. Take in a hosta convention, regional events are inexpensive and allow plenty of time to socialize. Visit other local gardens and get some new ideas. Remember to bring a hosta along as a gift. Begin to plant new acquisitions.

Late Summer (Growth of buds for next year) late-August-September

Hosta 'Lakeside Little Gem' blooming With the full extension of the flowering inflorescence, the growing tip, (meristem), of the hosta shoot is carried high into the air, at the end of the scape. New “dormant” buds now begin to form at the base of the scape, that will go through cold dormancy and produce the new shoots and leaves of the plant in the next spring. Ideally, three buds are formed, but frequently less are formed by large hosta cultivars. In some early flowering hostas, these buds may produce a second growth of new shoots, leaves, flower scapes and more dormant buds the same summer, especially if they are grown in areas where the growing season is long, as in the Southeastern US.

Labeling: Place plant labels, temporary or permanent, with each new hosta. Bury a plastic label with the plant name in pencil in the same position for each hosta. Map garden if you are so inclined.

Light: Days begin to shorten, hostas begin to look tired.

Nutrients: Fertilize newly planted hostas with 10-10-10 or a little slow release fertilizer. If some hostas make a few new leaves then liquid feed once in August.

Pests: Check for voles moving into the garden. Check for foliar nematodes, again. Check the oldest leaves. If the deer still want your hostas, then at some point, open the gate and let them clean up the garden for you.

Protection: Mulch newly worked areas.

Propagation: Continue to divide hostas. Try to get them finished 6 weeks before the first frost. You can do it later but remember hostas do not grow roots over the winter.

Water: Turn off the irrigation and put the hoses away. Lack of water will encourage dormancy. Of course, continue to water your new plantings. I use a watering can.

Fun! Look for fall specials from your favorite hosta nurseries. Hostas planted in the fall will look a year older than the ones you buy next spring. Continue to plant new acquisitions. Start collecting seeds from early flowering hostas.

Fall (Maturation of seeds and onset of dormancy) late September-October-November

As the days shorten toward winter, hostas prepare for dormancy. As the chloroplasts begin to break down and the bright yellows of hidden pigments, caroteins and xanthrophylls, begin to appear, green hosta leaves turn to gold. The leaves then begin to dry and petioles weaken and droop. The dry air helps the ripe seed pods to spring open, allowing the seeds to fly away on the wind. Usually it takes two or three hard freezes to knock the shriveled hosta foliage to the ground, while the flower scapes will persist intact through the first snows of winter.

Hosta garden Labeling: Make sure every hosta has a label before it becomes unidentifiable. The ones in pots probably need a new label as well. They tend to fade over the winter.

Light: The leaves are falling and the light continues to fade never the less. The days shorten inducing dormancy.

Nutrients: None needed.

Pests: Only the voles are a problem now. Begin to bait and trap again.

Protection: Remove tree leaves from the garden to discourage the voles from moving in. I use a leaf blower and not a rake. Finish cutting flower scapes. Apply mulch to your new plantings and touch up as needed.

Propagation: Hurry up! It is almost too late.

Water: Make sure your hostas are full of water the night before the first hard freeze. Usually rain comes with the first real cold front of the season, but if the fall has been dry you might need to soak the garden one more time before you lock the pump house for the winter.

Fun! Collect a few seeds and plant them right away. They will be up in 2-3 weeks and you will have a few hostas to play with all winter. Cheer up. I know your hostas look terrible now, tired from another full turn of their life cycle. This last sad memory of them as they retire for the year, I believe, just makes them look that much more perfect when they emerge with their fresh leaves next spring. Take a break, you have earned it!

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