Pat Curran

Almanac: May-June 2108

by janem on May 5, 2018

What To Do in the Garden in May & June

Basil seedlings

May Edibles:
It’s your last chance to start some slow-growing seedlings early in the month, such as tomatoes and parsley. Soak parsley seeds in lukewarm water for a few hours first. Consider getting a heated germination mat to accelerate germination. After germination, take the plants off the mat and hang fluorescent lights about four inches above them. It’s OK for seedlings to have the lights on 24 hours a day—it will accelerate growth.

Around May 10is when I start heat-loving, long-season plants such as winter squash, melons, and okra. Cucumbers and summer squash can also be started then, or you can wait until later in May or June, and seed them directly outdoors, as they are faster growing.

Early in May, there is still time to direct seed some of the cool-tolerant veggies, such as spinach, lettuce, and radishes, that are quick to harvest. It’s probably too late to plant peas, because they won’t produce before the real heat arrives.

Late in the month (or early in June) should be safe to plant your frost-sensitive, heat-loving seedlings outside, especially if you applied black plastic or IRT (infrared transmitting) mulch to warm up the soil in the veggie garden. Use rowcover to keep the plants warmer and prevent early insect attack. For real heat lovers like melons, you can leave the rowcover on for a few weeks, but be sure to remove it when they start blooming.

Now is a good time to fertilize your blueberries with the acid fertilizer ammonium sulfate (notaluminum sulfate), and/or apply elemental sulfur to keep the pH acidic enough.

May Ornamentals:
The average last frost occurs in mid-May in much of Upstate NY, but frosts in late May are quite common in some areas. Be prepared to cover sensitive perennials such as Japanese painted fern, kirengeshoma, true lilies, and even hostas, if a hard frost is predicted. I keep old blankets and sheets for this purpose (do not use plastic).

May and June are the best times to prune those woody plants that are considered “bleeders.” Maples, birch, yellowwood, magnolia, linden, willow, and nut trees are just a few trees that are best pruned in this time frame, after the sap is finished running. Peach trees are also best pruned when in bloom or just afterwards (see the Cornell Guide to Growing Fruit at Homefor details).

The first part of May is still a good time to divide hardy perennials such as daylilies, hosta, and phlox. It’s also when fall bloomers like asters and mums can be divided. Be sure the roots are moist first and be prepared to replant (or pot them up) immediately. After transplanting I use milk crates or buckets to keep the sun off for a couple of days if the weather turns hot and sunny. Now is a good time to pot up (or move) seedlings if you’ve allowed your perennials to self-sow. If you have double-flowered peonies, you should install peony cages early in the month to support the heavy blooms.

Keep applying deer repellent on the succulent new growth as needed.

Prune early-spring–flowering shrubs like forsythia right after they bloom.

Check your ash trees for emerald ash borer and decide if treatment or removal is warranted. Young, healthy trees respond to treatment better than old, declining trees. If you have considerable land, consider leaving some ash trees alone, in case they prove to be resistant.

Either April or May is a good time to use your germination heat mat for getting heat-loving tropical “bulbs” such as caladiums started. Use shallow pots until they sprout. Depending on your microclimate, you may need to pot them up again before they can be safely planted outside. Other tender bulbs or tubers, such as dahlias and cannas, can also be potted up early, but should grow at normal indoor room temperature.

Keep your lawn mower set to three inches or higher, be sure the blade is sharp, and mow frequently as needed. Wait until early fall to fertilize, will encourage root growth rather than top growth.

June Edibles:
Keep up with the weeding! Don’t let the weeds go to seed. After the soil has warmed up sufficiently for peppers and tomatoes, go ahead and put down mulch. Stake or cage your tomatoes before it’s too late. Plant Brussels sprouts transplants. There is still time to sow cucumbers and summer squash. Plant carrots in late June to avoid the carrot maggot, which usually has only one generation a year.

Now it’s time to harvest peas and strawberries! Juneberries (a.k.a. amelanchier or shadblow) will be ripe in May or June also. Finish harvesting rhubarb and asparagus by mid-month.

After fruit trees drop their excess, thin the remaining fruit as needed to get bigger, better fruit (see the Cornell guide cited above).

Install a rain gauge or consider getting an electronic weather station that delivers data such as temperatures, wind speed, and rainfall inches to a display inside the house.

June Ornamentals:
Keep weeding!

Pinch or cut back perennials (before the end of the month) that bloom in late summer or fall, in order to make them shorter and bushier—asters, mums, boltonia, etc. See The Well-Tended Perennial Gardenby Tracy Di Sabato-Aust for details.

Deadhead peonies, bearded irises, and rhododendrons, among others. Look for iris flower fly maggots, especially in Siberian iris, but also in bearded iris.

Dig up spring bulbs that need dividing (leave daffodils to the last to allow the foliage more time to feed the bulbs).

Mid-June is the usual time to take softwood cuttings from deciduous shrubs.

Early in June, it should be safe to move some houseplants outside for the summer. Avoid sunburned leaves by siting them in some shade.

Go on garden tours—they are great fun and there are lots of ideas to borrow from fellow gardeners!

—Pat Curran and the Tompkins County Master Gardeners


Almanac: September-October 2107

by janem on August 31, 2017

What To Do in the Garden in September & October

Hairy bittercress

Hairy bittercress


The best time to renovate or install a lawn is late August through September. Cooler, longer evenings and moist weather encourage root growth. It’s easier to keep the seedbed moist for germination, and annual weeds such as crabgrass will be unable to set seed before frost.

Plant colchicum and the true fall crocus bulbs as soon as they are received. Otherwise, Colchicum may bloom in the bag! Go ahead and plant them anyway, and they will be ok.

Replace tree guards around vulnerable tree trunks to prevent “buck rub” deer damage.

Start planning to bring houseplants inside, especially tropicals. This allows for an adjustment period (maybe even quarantine in case they have pests). Holiday cacti and cymbidiums need cool temperatures to set flower buds, but not cold or frost. A cool room inside should suffice.

It’s your last chance to plant veggies outside—only radishes and maybe spinach are fast-growing and hardy enough to get a crop. Consult

Plant a hardy cover crop such as winter rye in vacant garden spaces. Otherwise, I sheet-compost there instead (flattened cardboard covered by leaves).

Consider planting hardy veggies in a cold frame or low (or high) tunnel for winter crops. Think about overwintering potted herbs on a sunny windowsill. I have had good luck with basil, parsley, and sage. Rosemary needs careful watching and watering, as it doesn’t wilt when dry, it just dies.

Keep up with the weeding, but ease off on the deadheading. Roses, for instance, will be better prepared for winter if allowed to set hips.

Visit your local nurseries for great sale plants. Also, tour display gardens and note what is blooming now. There are many fall-blooming perennials besides mums! Hybrid anemones that have not become invasive at my house, even after 20 years, are ‘Honorine Jobert’ and ‘September Charm.’ Cimicifuga ‘White Pearl’ is a fragrant late bloomer susceptible to early fall frosts, so plant it in a sheltered part shade location. Ditto for Korean wax bells (Kirengeshoma spp.) and hardy begonia (a zone six plant that has overwintered for me several years in a sheltered spot). Mark the hardy begonia well since it doesn’t come up until almost June. Fall monkshood is very frost-hardy and brings that deep marine blue to the garden (remember it’s poisonous, though). There is even a late-blooming hosta called ‘Red October’, but only the petioles and flower scapes are red.

Divide and replant hardy spring-blooming perennials as soon as possible. You can also move or divide the hardier perennials such as tall perennial phlox, hosta, or daylilies. Avoid disturbing shallow-rooted perennials like heuchera that are prone to heaving.

Make maps or take pictures of your plantings before the first frost hits and the leaves fall. Replace labels if needed. Pencil lasts a long time on plastic labels and doesn’t fade in the sun. Take notes about what needed to be moved/divided/replaced next year. Finish planting container perennials and woodies. Keep them well watered. I mulch right after planting to allow more root growth before the soil cools off too much, despite the usual recommendation to wait until the ground freezes.



October is the best month to move peonies (both herbaceous and tree peonies, if necessary, but this is a big job!). We dig, divide, and pot up herbaceous peonies in October for the May plant sale, and most of them will bloom in the pots around sale time. It’s also the best month to dig up and divide hardy lilies. Its time to finish planting your spring-flowering bulbs outside! I mulch crocus and tulips with pea gravel to deter the critters that might be inclined to start digging. Start potting up the hardy bulbs you want to force (you can finish this task in November). Protect potted crocus and tulips from mice.

Mid-October is the best time to plant garlic. Be sure to rotate the garlic to a well-drained area, and mulch after planting. It’s recommended to plant the biggest cloves and save the smaller ones to eat.

Late October is a good time to start cleaning up around your perennials. Consider cutting down dead stalks (except for mums, Japanese painted ferns, kniphofia, and semi-woody plants like lavender, sage, Russian sage, and butterfly bush, which overwinter better with the protection of the old stalks). You may choose to leave stalks in place for winter interest (sedum, e.g.), birdseed (echinacea, black-eyed Susan, e.g.), or overwintering beneficial insects, including pollinators. Pull those winter annual weeds that have sprouted! Hairy bittercress (Cardamine hirsuta) is a particular pest because it blooms at such a tiny size. If you see little clumps of circular white objects resembling tapioca, those are snail or slug eggs. Get rid of them (not in the compost).

This is my best opportunity to apply mulch because my flowerbeds are full of bulb foliage by early spring.

Use your mulching mower on the leaves on the lawn, if possible. Consider collecting leaf bags from your neighbors! I have a special compost bin for leaves. I leave them in the bags (plastic preferred) until the leaves turn into “leaf mold”, which is my main organic soil amendment. Most leaves are wet and ‘dirty’ enough to compost right inside the bag. Any really light bags contain dry leaves—these are set aside for use as mulch in the veggie garden the next season.

Clean up all the old veggie plants, debris from the veggie garden, and fallen fruit. Although most recommendations are to dispose of this in the trash, I have too much to do that. Instead, I put it in a long-term inactive compost pile, so I’m isolating diseases and pests that the debris may hold. Applying fresh mulch will help isolate disease organisms. Be sure to protect fruit tree trunks up to four to five feet above the ground from nibbling wildlife.

Continue preparing to protect vulnerable plants from deer, rabbit, and rodent damage – with fencing, hardware cloth (which is actually wire), plastic tree protectors, and/or repellents.

Move a bucket of good garden soil and/or woodchips into a freeze-proof location. This can be used during winter thaws, to cover the roots of frost-heaved, shallow-rooted perennials such as heuchera. Otherwise, heaving causes the roots to dry out, and generally the ground is still frozen enough a few inches down to prevent replanting. This tip is from the late Elisabeth Sheldon, author of several excellent gardening books, who used to have a nursery near Ithaca.

It’s too early to wrap evergreens in burlap, but not too early to get prepared. The goal used to be to prevent winter wind and sun from desiccating and killing the foliage, especially of broadleaf evergreens such as rhododendrons and hollies. This is still important, and despite the controversy about them, I have been applying antidessicant sprays the last few years, but generally not until Thanksgiving or even later. But now with global warming, early spring damage has become just as important. Warm weather in March is no blessing when it is followed by drastic cold snaps that kill twigs, buds, and leaves that have become de-acclimated. Be sure not to let woody plants go into winter in a drought-stressed condition.

—Pat Curran and the Tompkins County Master Gardeners


Almanac: March-April 2017

by janem on March 17, 2017

March Edibles
Start onion/leek/celeriac seeds early in the month. Consider getting a heated germination mat. After the seeds germinate, take the plants off the mat and place about 4 inches below hang fluorescent or LED lights.

Start pepper, eggplant, and parsley seeds late in the month if you are in zone 6 or a warm microclimate of zone 5 (otherwise, early April). Soak parsley seeds in lukewarm water for a few hours first. Use the germination mat. Move to the light setup as soon as the seeds sprout.

If you have overwintered vegetable plants in a cold frame, make sure they don’t get overheated. If there are root veggies in the garden, dig them up as soon as you can before they resume growth or rodents get to them. Harvest overwintered leaf veggies (FEDCO Seeds has a great list of extra-hardy veggies that can be wintered over with the help of a cold frame or low tunnels or mulch.) Egyptian onion, also known as perennial or walking onion, needs no winter protection and provides an early harvest.

It’s time to start pruning fruit trees (except peaches) and grapes, before they leaf out. If you grow fall raspberries, and prefer to get the large crop in late summer and fall, prune all the canes down to the ground. ‘Polana’ is a great variety that fruits for over two months starting in mid-August. I avoid ‘Heritage’ due to late fruiting and susceptibility to Phytophthora root rot.

March Ornamentals
Observe where the snow melts first. This is your warmest microclimate. Consider putting your earliest spring bloomers there, such as snowdrops, winter aconites, and hellebores. Also, keep track of where the snow lingers longest. This is your coolest microclimate. When designing  your landscape, consider this site for plants that tend to sprout too early and get damaged by late spring frosts. By mulching heavily and siting them in a cooler spot, they will stay dormant later and hopefully avoid such damage.

Watch out for water that accumulates on top of frozen ground. Consider covering sensitive alpines with a bucket or plastic box to prevent this. Water puddles can kill evenwinter-hardy plants such as purple poppy-mallow. Plant them on a slope to allow the water to drain away.

Winter is a great time to plan garden improvements because the architecture of your design is most apparent then. Take a photo of an area of your garden, and print it out on 81/2” x 11” paper.  Tape a sheet of tracing paper over the photo and, with a pencil, sketch shapes and sizes that you might like to add to the picture. Sketch circles and sweeping lines of various lengths for shrubs and grasses. Use a stick and ball to represent flowering perennials. Is there a view you would like to maximize or hide? Use colored pencils to enhance your design.

Now is also a good time to evaluate and prune your ornamental trees and shrubs, except for species that are considered ‘bleeders’. Maples, birch, yellowwood, magnolia, linden, willow, and nut trees are just a few trees that should be pruned a little later, after the sap is finished running.

This is a good time to repot houseplants and resume fertilizing lightly. Look for problems such as insects. Leggy plants such as angel wing begonias can be pruned and the cuttings rooted.

April Edibles
Start tomato, broccoli, cabbage, and basil seeds indoors in mid-month (if you will have enough space under your fluorescent lights). Start fava beans in individual cells or pots late in March or early in April, depending on your microclimate. This is a bean that tolerates light frosts, so plant the seedlings outside later in the month, to get production before hot weather.

In late April, move pepper, eggplant, and basil seedlings to individual pots indoors. Consider applying black plastic or IRT (infrared transmitting) mulch to warm up the soil in the veggie garden where you want to plant heat-loving crops.

If spring weather permits, direct-seed cold-tolerant veggies such as peas, spinach, lettuce, radishes and carrots around midmonth.

Finish pruning fruit trees (except peaches) and grapes before they leaf out. Prune berry plants per recommendations. Consider applying row cover on strawberry plantings. Fertilize blueberries with an acid fertilizer such as ammonium sulfate (NOT aluminum sulfate) and/or apply elemental sulfur to keep the pH acid enough.

April Ornamentals
Protect early-sprouters from late spring frosts. Candidates for protection include the true lilies, Japanese painted fern fiddleheads, Kirengeshoma species, and crown imperial, all of which have been zapped one time or another in my zone 5 frostpocket location. You can use the same covers that you employ to protect your tomato plants in fall: old sheets and blankets that are not too heavy, cardboard boxes, or upside-down buckets. Avoid using sheet plastic and tarps. Do not rush to cut off last year’s foliage as it does protect the crown and emerging sprouts.

Early April is a good time to divide Solomon Seal before the stems elongate, and bloodroot before it sprouts. Later in the month, it may be time to remove last year’s stalks from mums, and divide the clumps if needed. Also, it’s a good time to divide many hardy perennials such as phlox, Siberian iris, Hosta, daylilies, asters, Helenium, Boltonia, Heliopsis, Shasta daisy, and so on. Bearded irises may be divided, but they probably won’t bloom this year. Lavender, culinary sage, Russian sage, and butterfly bush can have dead wood trimmed off late in the month, when winter damage and live buds can be distinguished.

Protect crocuses and tulips from animal damage. Crocuses are particularly vulnerable because a new corm needs to be formed each year; they do not have persistent true bulbs like tulips. A mulch of pea gravel helps to discourage digging, and then repellent sprays are needed once they sprout. A deer fence helps, but I suspect rabbits may also browse on the foliage.

If the spring is dry, and you have plantings that receive salty runoff, water them heavily to flush the salt down below the root zone. Prune off branches damaged by salt spray, and make a mental note to install a burlap screen to prevent salt damage next winter.

Use your germination heat mat for getting heat-loving tropical ‘bulbs’ such as caladiums started. Use shallow pots until they sprout. Depending on your microclimate, you may need to pot them up again before they can be safely planted outside. Other tender ‘bulbs’ such as dahlias and cannas can be potted up early, but should grow at normal indoor room temperature.

— Pat Curran and the Tompkins County Master Gardeners