Every year at the UConn Home & Garden Education there are a few topic of interest that we get a lot of calls about. Several years ago we fielded a lot of calls about the drought situation in Connecticut that occupied many people’s thoughts in 2016. In fact, that encompassed two years as we started to feel the effects of it in 2015. On the tail end of the drought, and perhaps in part because of it, many parts of the state were visited with an infestation of gypsy moth caterpillars. When we have a wet spring the fungus Entomophaga maimaiga, a natural control of the gypsy moth caterpillar, can flourish. The fungus overwinters as spores in leaf litter and in the soil. It then reactivates in the spring when there is sufficient rainfall. Although we were receiving an adequate amount of rain by 2017 it happened to occur a bit late for the fungus to be fully effective against the voraciously feeding caterpillars. So the summers of 2016 and 2017 were dedicated to answering many questions about the gypsy moth caterpillars and the damage that they wreaked.

As those two events have wound down a new concern arose for many of our clients. Thanks in part to press releases and an interview that aired on NBC CT in June the giant hogweed, Heracleum mantegazzianum, (below images) jumped to the front of the queue. The Connecticut Invasive Plant Working Group (CIPWG) issued a warning about this invasive species which was first spotted in Connecticut in 2001. Most of the populations of giant hogweed are under control and none of the reported sightings in 2018 were positive.

There are many look-a-like plants and it is those species that we are asked to identify. Starting in early-June calls and emails began to come in to identify large herbaceous perennials that were striking fear into Connecticut residents. This is in part due to the pretty noxious nature of the giant hogweed sap. Within 24-48 hours after skin has been in contact with the sap painful blisters may appear in individuals that are sensitive to it. Three things need to be present for the reaction known as phytophotodermatitis to occur. First, direct contact between the skin and the sap. Second, the skin must be moist as from perspiration, for example. Third, the contaminated area must be exposed to sunlight. If you are working in an area that contains giant hogweed it is easy to imagine that all of the criteria could be easily met.

Before attempting to remove giant hogweed from an area the first step should be positively identifying it. As I mentioned earlier, there have not been any confirmed sightings in Connecticut yet this year. It may be that the suspected plant is one of the following instead.

The first plant that is most commonly mistaken for giant hogweed is fellow member of the Heracleum genus: cow parsnip, Heracleum maximum, (images below). Unlike giant hogweed which was introduced to the United States 100 years ago from the Caucasus region of Central Asia, cow parsnip is native to North America. A tall herbaceous perennial that can reach up to 10 feet in the shade, nowhere near the 18 feet possible height of the giant hogweed, cow parsnip bears its flowers in in the flat-topped or rounded umbels that are characteristic of other members of the carrot family, Apiacea. Both species have compound deeply-lobed, toothed leaves but the cow parsnip lacks the red veining and leaf stalks common to giant hogweed. Cow parsnip also contains chemicals that cause phytophotodermatitis.

The next most common look-a-like is angelica, (below images). A first cousin once-removed, it shares its family, Apiaceae, with the giant hogweed and cow parsnip but is in the genus Angelica. Angelica grows 3-9 feet tall and also has large umbel flower heads. The compound leaves of angelica are what distinguish it from giant hogweed as they are bipinnate, meaning that they are compound leaves in which the leaflets are also compound (think honey locust leaves). Often used as a medicinal herb, angelica is the least toxic of the hogweed look-a-likes although it may still cause a skin reaction.

Queen Anne’s lace, Daucus carota, (below images) takes compound leaves one step further to tripinnate, having pinnately compound leaves that are bipinnate. The more levels of pinnation, the more delicate the overall effect. The airy-looking leaves of D. carota are what give it the ‘lace’ part of its name and are similar to its subspecies, the domestic carrot. Queen Anne’s lace has an umbellate flower head atop a much slimmer stem than giant hogweed, cow parsnip, or angelica. The sap from the leaves and stems can cause a phytophotodermatitis reaction although the flowers are used to make jelly similar to the yarrow jelly from our June 26th blog post.

The native Lactuca species includes wild lettuce (Lactuca Canadensis),

prickly lettuce (L. serriola), hairy lettuce (L. hirsute), and the blue lettuces (l. biennis, L. floridana, L. pulchella, L. villosa).

These tall plants start out from a basal rosette of leaves and can grow to 7 feet tall with large alternating broad leaves.  They have pale blue insignificant flowers compared to the dense clustered heads of the previous plants.

Finally, giant ragweed, Ambrosia trifida, has also made a plant identification appearance.  This 6-foot tall annual herb is a noxious weed that has become invasive in other parts of the world as it out competes native species in much the same way that the giant hogweed has here.

As plants and seeds have spread across the globe through human, animal, mechanical, or water means many species have landed in non-native locations and taken root there. If you are a fan of podcasts, check out the Infinite Monkey Cage’s Invasion episode where scientists and comedians take a look at the problems caused by alien (plant) invasions.

Susan Pelton, UConn Home & Garden Education Center

All images by CIPWG and UConn



After a long, busy day at work, I like to find an hour or two most evenings to work out in the garden. It is cooler then and sometimes a soft breeze can be had. I do have a bit of hand watering to do with 32 thirsty container plantings but then I can plunk myself down in the aromatic herb garden or amidst the vegetables or in one of several perennial/shrub beds and pull up weeds. While it sounds crazy to most, this is relaxing horticultural therapy for me. It gives me time to let my mind wander and pleasure at seeing a weed-free garden bed, and also keeps me in touch with what is happening in the garden and in the yard.

Ideally, mulch of some kind would get put down after weeding but this does not always occur in a timely fashion. A few beds were mulched with a bark mulch but with the hot, dry weather, the surface of the mulch has become hydrophobic (water resistant) and one has to either keep the sprinkler on for a long time or ‘prime’ it by poking a few holes in the mulch around the base of the plants to let the water penetrate and not roll off. I am having this problem because of late plantings (some last weekend –great summer sale at local garden center!). So I have overgrown 6-pack plants in small holes in very hot and dry weather. The root zone needs to be soaked every day and the bark mulch is repelling water.

Back to weeding. I found 3 Large Cabbage White caterpillars in one of my ‘Gonzales’ mini-cabbages. They were promptly removed and squished. Two other caterpillars to look for on members of the cabbage family are the imported cabbage worm and cabbage looper. They all seem to like green cabbages better than red ones. Hopefully that goes for Brussels sprouts too as I planted “Rubine’ red ones this year.

Damage from cabbage moth larvae

Dill self-seeds itself throughout the garden. This is great when drying the leaves for culinary purposes but there is a limit as to how much dill weed one can use. Many dill plants are weeded out but not before I check to see if there any eggs or larvae of the black swallowtail butterfly – aka parsley worm. Plants with caterpillars on them are left alone.

Parsley worm on dill

Not one honeybee to be seen but in these later evening hours, bumble bees and other native pollinators are still active. They really like the leeks that made it through the winter and are in full bloom. Good reading on the decline of our native bumble bees and what to do about it can be found in Conserving Bumble Bees. Guidelines for Creating and Managing Habitat for America’s Declining Pollinators from the Xerces Society.

In the herb garden I get to munch on pineapple strawberries and bronze fennel leaves while weeding. A cocoa hull mulch will go on this weekend. Most years there is a leopard frog or two living in the thyme bed but this year only grasshoppers are jumping about. Garlic chive seedlings are prolific as that October snowstorm dashed seedheads to the ground before they were deadheaded. Two of the four tri-colored sage plants overwintered but curiously several branches of plain-colored sage emerged from each plant and are now blooming. I suppose I should cut them off but the bees are so enjoying the blossoms.

Last year all leaves were variegated – this year plenty of green!

Early evening also brings avian visitors to the yard. The bird baths and feeders get filled then and cardinals, goldfinches, chickadees, nuthatches and more line up for food as if knowing what they don’t eat now will probably be consumed by the squirrels in the morning. The past few days a couple of juvenile red-winged hawks have been chasing each other in the back woods and putting up quite the ruckus. A wren perches on the tomato stakes as if to check out my work. The spicy perfume of nicotiana permeates the area. Crickets softly chirp. Life is good!

A very bad picture of a very noisy young hawk!

(Uh oh – mosquitoes buzzing – time to go in!)

Soil –fully yours!


October is in its  second week, bringing the first hard frost to the middle of Connecticut. This seasonal mile stone is my cue to plant garlic. I know, planting anything in mid October seems like the wrong thing to do and a bit backward, but now is the correct time to plant the strong scented bulbs. There are about six weeks left before the ground freezes, giving the garlic ample time to develop a good root system without producing any top growth that will be killed with the freezing weather.

Pick the right spot.

Garlic needs a full sun spot with well drained soil rich in organic matter. Full sun is 6 to 8 hours of sun a day. Add a one inch layer of well rotted manure or compost and mix in with existing soil. Loosen soil to about a foot deep. Have a soil test done to determine pH and nutrient level after compost or manure has been added. Garlic grows best in a soil pH of 6.5 to 7.0. Add lime and any amendments as soil test results recommend.

Break the head of garlic into individual cloves. Leave the papery skins on the cloves. Plant with the root end down and the pointed tip up, three inches into the soil, with each clove spaced six inches apart. A fluffy mulch of straw covering the bed for the winter will provide protection from heaving during the freezing weather. The goal is the encourage root growth this fall, not top green growth until spring.  Once warm spring weather initiates green growth next spring, side dress with a little 5-10-10 fertilizer at a rate of 1/2 pound for 50 garlic plants.

Pick the right garlic.

There are three different types of garlic:   softneck,   hardneck   and elephant. Choosing the correct type to grow for your area will bring the most success.

Soft neck garlic is not well suited to grow through our cold New England winters. It has a soft neck, papery neck of a stem good for braiding. Soft neck garlic is most often the type seen for sale in the grocery stores, shipped in from California where it is grown. Do not plant this in Connecticut.

Hardneck garlic is best suited for New England gardens. It has a hard, almost woody center stem with six to 12 cloves surrounding the central stalk. This type will produce an edible scape that if left on the plant, will produce a flower. The flower will sap strength from the bulb making the cloves smaller. Cut off the scapes before they bloom in May or June. Common hard neck varieties include ‘German White’,  ‘Music’, and ‘Spanish Roja’. Hard neck garlic can be purchased through seed catalogs and most commonly available at farmers’ market during September and October. They are sold to eat, and these can be used as seed stock for planting.

Elephant garlic are very large heads the size of tennis balls with a mild taste.  It is not actually a garlic but closer to the leek family. I have not had much luck getting elephant garlic to live though the winter successfully. Stick with the hard neck varieties!

Harvest and Storage.

During the month of May, the each plant will put up a tall scape with a bud at the tip containing a future flower. As stated earlier, don’t let it flower. Cut the scapes off of the plant about two feet above the ground. The scapes are the first harvest provided from the plants. Garlic scapes are sharp in taste, considered a spring delicacy in stir fries or made into a pesto.

The real harvest of the bulbs comes when the greenery begins to turn yellow and papery. Each above ground leaf is a layer of papery sheath for the cloves below. Handle the plant carefully without damaging the protective paper covering of the head of cloves. When about half of the leaves have turned yellow to brown, harvest the bulbs. Gently dig the heads and lay them in the shade  to dry for two or three days. Protect from night dew to promote the drying. Good airflow is essential. Leave the roots, stalk and leaves on the plant for a month. Set out of the sun, in a covered airy location to cure the garlic. The curing develops the taste and keeping quality.   Do not wash with water. After curing and drying, cut the roots to half inch and bush off any dirt.Garlic can be stored in mesh bags or braided by the stems.


photo by Carol Quish

photo by Carol Quish

Crabgrass is overtaking some lawns by this time of late summer. It is an annual grass weed with wider blades and lighter yellowish green color than the preferred lawn grasses. Crabgrass seeds that germinated last spring are large spreading plants by September. The cooler soil temperatures at the end of summer trigger new plants to sprout, adding to the crabgrass population. All crabgrass plants will die with first the hard frost. As stated above, they are annual plants meaning they grow from a seed to plant, produce seed and die all in one year. Each year, new plants grow from seed make up the entire crabgrass population. Knowledge of the plant’s growth cycle is useful for using the correct control measure.

The first line of defense against crabgrass is healthy soil and a dense stand of turf. Soil pH for turf should be 6.5. Connecticut soils usually are in the below 6 range. A soil test will determine your particular yard’s pH level as well as reveal the nutrients available. Soil testing how to’s can be found at www.soiltest.uconn.edu. After receiving results by mail, make recommended additions to bring your soil into optimum grass growing condition. Turf needs oxygen and water also to support a healthy lawn. If soil is hard to dig and compacted, now is the time to core aerate. Aeration machines remove a small plug of turf and soil, depositing it on the lawn surface. Leave these plugs on top, do not rake them up. Rain or watering and wind will breakup the plugs, redistributing the soil microbes into the top layers. If you want to add more organic matter to the soil, spread a thin, (1/4 inch), of compost over the entire lawn. Compost will add rejuvenating microbial life to the root zone of the grass.

Mid September is the ideal time to overseed bare and thin turf areas. Choose a grass seed mixture that contains a high percentage of fescue grass. Some bluegrass and perennial rye grass is usually included in the mix. Do not chose one with annual ryes as these will die with the cold weather.  Rake the bare spots to break up any crust to give the seed good contact with the soil. Tamp down after spreading seed. Keep seed moist during germination occurs and new seedlings are two inches tall. Next spring, this new grass should fill in nicely.

To keep the crabgrass seed from germinating in the spring, use a pre-emergent herbicide. Crabgrass begins to germinate when the soil temperatures reach 38 to 40 degrees F. Forsythia blooms at the same soil temperatures making it a good plant indicator to help with remembering the timing of herbicide application. Pre-emergent herbicide does not kill the non-germinating seed, only the new little pip emerging from the seed. This new tissue, the pip, is very tender and susceptible to the chemicals in the pre-emergent herbicide. Not all the crabgrass seeds will germinate every year. Some will stay dormant for many years, creating a seed bank. Each year crabgrass is allowed to grow and produce seed, it adds more seeds to the seed bank. Read the label of the pre-emergent to see how long it will last. Some formulations will last two months, some last six months. These anti-germinating chemicals halt the germination of all seeds, broadleafed and grasses. Only one, Tupersan allows desirable grasses seed to germinate. Tupersan only works on the crabgrass seed, but it doesn’t last long, two months most labels advise. An organic option of pre-emergent herbicide is corn gluten meal. Timing is the same as with a synthetic pre-emergent.

Fertilize with the amounts indicated on the soil test report. Starter fertilizer may be used at the seeding stage.

So to recap the step needed to thicken the turf and reduce crabgrass:

1. Soil Test – apply lime as recommended

2. Core Aerate

3. Top dress with compost.

4. Seed with high fescue seed mix.

5. Keep moist.

6. Next spring when forsythia blooms, apply a pre-emergent herbicide.

Result is a lush healthy lawn.


Mid August brings heat and harvest chores.  I must pick daily to keep up with the plants. Cucumbers, summer squash, beans, peppers and tomatoes fill the baskets. It seems the vegetables are growing fast but then I see the weeds are growing faster!

I went to Maine for a visit to the Coastal Maine Botanical Garden. I highly recommend a visit if you find your self in the Boothbay area. I saw gardens of all kinds and sculptures artfully placed in outdoor spaces. Children are invited to create fairy houses with natural material for the fairies that live in this glorious setting. Another excursion was to Endless Summer Flower Farm, a dahlia and perennial farm located in Camden, Maine. Owner Phil Clark graciously engaged us with his 230 varieties of dahlias, all growing in his back yard and side field. Just glorious, enticing me to purchase tubers to be delivered in the spring. A flower bouquet of cut dahlias was brought back to my hosts. The flowers were very beautiful. Maine gardeners have a slightly shorter growing season and many of the same weeds as I do in Connecticut.

Now is the time to keep up the the weeds. Any plant allowed to produce will become weeds in the next several growing years. This year I discovered cilantro in every nook of open soil. While I didn’t mind the herb earlier in the season, now they have all grown four foot high with seed pods containing the spice coriander. I am trying to collect the seeds in paper bags before they burst. Once captured I store them in glass jars in the spice cabinet for crushing the seed with a mortar and pestle when I have a recipe calling for ground coriander. The leaves can be dried and saved as an herb, but should be done before the flowers form. Dill spreads in much the same way as cilantro. Both herbs have become a weed in my vegetable garden.

Other weeds having a ‘field day’, (pun intended), are crabgrass and galinsoga. Galinsoga will set flowers at the tender age of eight weeks.  It produces over 7500 seeds per plant. Seeds require no cold period, so they can germinate as soon as they mature and drop to the ground. Many seeds will overwinter, germinating next year and in subsequent years. Crabgrass is an annual that will die with the first hard frost. If allowed to produce seed, you can be sure seed produced this year will germinate in early spring next year making the weed problem worse.

I use mulch in the pathways to keep the weeds down, but the wood chips brought in harbored their own set of weed seeds. I now have fox grape, a semi-woody vine, that is difficult to pull out. I feel I will be fighting this one for a few years to come. Some people use hay on the gardens as mulch. Use straw instead, it contains less seed. Hay will add not only weed seeds but grassy seeds intended as animal food. Straw is more woody, breaks down slower than hay and is usually cut before it gets to the seed production stage. Bark mulch is a great alternative usually not infected with any weed seeds. A living mulch of clover can be used in pathways, especially if you have raised beds. Once the clover grows taller, mow or weed wack it down to a desirable height.

All of this pick of produce and pulling of weeds makes some glad the summer season is closing. But the fall growing season is just beginning. As the weather cools down, all the crops grown in the spring time can be grown again in the fall. They are, after all, cool weather crops. I start lettuce, spinach and kale directly in the garden for fall harvest. Root crops of carrots, beets, parsnip and turnip can be planted now. If the ground temperature is too warm for germination, start flats inside the house out of the sun’s direct heat. Transplant when at the two leaf stage.

I keep a bed of mixed lettuce specially chosen for cold tolerance. The other half of the bed is put in spinach. I have a 2 x 4 wood frame attached to PVC pipes covered with painter’s plastic to create a small greenhouse tent. Hinges were added so it can be easily lifted and opened. This fall crop of greens will keep producing well into December before it goes dormant for a few months. Come the last week of February and the first bit of longer sunny days, and these same plants come back to life. I prop the cover open on bricks if full sun is in the forecast so the plants don’t overheat. 100_8306100_8303

– Carol

I returned from a week of vacation to the find the gardens full of weeds! Everything grew like gangbusters in my absence. Those little weed seedlings grew to flowering stage in just a week! If we could only get the peppers and cucumbers to produce like that I would be happy. Mulch would have prevented many of the weeds from germinating in the first place. I also should have weeded well before I left instead of dealing with the larger weeds now. Hind site is always better.

I  gathered a large garbage bag full of seaweed from the beach. Once home I spread  it out on the lawn to rinse it thoroughly of salt and sand, let it dry in the sun and worked it into the soil of the beds of the finished peas, spinach and lettuce. I will replant different crops in these newly enriched beds. Leaf crops grow extremely well in seaweed amended soil. I love free fertilizers.

My tomato crop is slowly developing despite have spotted and yellowed leaves of septoria leaf spot fungal disease. Mulch would have helped here, too. Mulch provides a physical barrier between the soil and leaves above. The fungal spores of septoria live in the soil from year to year and can be splashed up onto the leaves of the tomatoes. Fungicides can be used before the infections happens to prevent the spores from growing on the leaves. Now it is too late. These spots start on the bottom leaves, progress to produce new fruiting spots that release more spores that land on higher leaves, moving the fungus from the lower leaves up the plant.

The non-stop rains and cool spring has brought the northeast the perfect conditions for another fungal disease, Late Blight, (Phytophthora infestans). This is the same fungus that caused the Irish potato famine in the 1850’s. We have identified the disease if both tomato and potato plants of commercial fields during the last two weeks. We will have to see how the remainder of the summer progresses relative to moisture to see how bad the outbreak becomes. Spores are spread by rain splash and carried by wind for up to several miles. The disease starts as a water soaked spot on the leaf,  stem or fruit, rapidly turning dark brown to black. The entire plant wilts and collapses.  Cornell has a great fact sheet here.

I would like to mention Magic Wings Butterfly Conservatory located in South Deerfield, Massachusetts this week. They are a butterfly conservatory open year round that folks can visit to see and walk among the beautiful creatures with their native plants. Another ‘beautiful creature’ is George who works there. A mother called me at the center last week looking for a source to purchase ladybugs to release at the funeral of her nine year old daughter’s friend. With only two days notice on Thursday afternoon, no commercial ladybug provider was willing to ship them to her in time. On a hunch, I called Magic Wings and relayed the information to George. They do not sell ladybugs but ladybugs do live in the conservatory with the butterflies. He came through magnificently! Mother and daughter drove to South Deerfield on Friday to pick up the box of ladybugs and thank George in person. They also visited the conservatory and several butterflies landed on the daughter. Quite a special experience for a grieving family. We at UConn add our thanks to George and Magic Wings.