Gardening in Winter

Red and Yellow Twig Dogwood
Red and Yellow Twig Dogwood

Warm winter days are the perfect opportunity to finish up some of the chores you might not have been able to get to in the Fall. Just be careful not to work on days when the soil is overly soggy. Walking in and out of your garden spaces can cause soil compaction. Here are a few things that you can do when the wind dies down and your energy is high:

  • Pruning – Almost any woody plant can be pruned this time of year. Just be careful with spring flowering shrubs; most of these set their flower buds last year at the tips their branches. Pruning plants like Azaleas, Rhododendrons, Weigela, and spring flowering Viburnums this time of year can leave you with little or no blooms.  But its a great time to do formative pruning on ornamental trees. Most summer-flowering shrubs prefer to be pruned while dormant, including roses. One of the first tasks landscapers do when they return to the field is Hydrangea pruning. If the pros can do it, so can you!
  • Garden Cleanup – If you take the time to clean up your garden now, you can take it easy and wait for the daffodils to pop up in their tidy beds this spring. You can cut down ornamental grasses and any perennials still left standing. Rake up the pine needles that have piled up on the lawn.
  •  Top Dressing – There is still time to top dress your flower and vegetable beds with compost or manure. The rain, snow and freezing and thawing of late winter will weather the nutrients into the soil. It only takes a few consecutive days of warm weather for soil organisms to begin breaking down the remaining organic matter on the surface, making nutrients available to your plants when they awaken in the spring.

Rosa ‘Blaze’

 

Rosa 'Blaze'Red roses are the quintessential Valentine’s Day plant. Of course, roses aren’t blooming in February on the island, but there are many red roses that do well on Nantucket.

Of the climbers, Rosa ‘Blaze’ is a standout variety. Introduced in 1932, ‘Blaze’ sports clusters of deep red, semi-double blooms on strong stems. Its leaves are glossy dark green and set off the crimson flowers extremely well. Although it is touted to be disease resistant, like all roses, the foliage can be effected by powdery mildew and black spot late in the season . Luckily, rust doesn’t seem to be an issue for us at the nursery with ‘Blaze’. If many of your roses suffer from rust, you may want to give ‘Blaze’ a try.

Like most modern climbers, this rose is “re-blooming,” meaning that it will have a big flush of flowers early in summer. This initial bloom period will be followed by a few blooms here and there until late summer to early fall. At that point in the season, ‘Blaze’ will have a secondary cycle of blooms, although not quite as magnificent as the first.

TIP: To perform their best, roses require some care. Heavy flowering takes a lot of energy, even for established plants. Deadheading helps redirect energy from fruit and seed production back into vegetative growth. To get the most out of your second bloom cycle, that energy is important. After the first flowers fade, cut all lateral flowering stems back to between four and six inches. This procedure also removes a lot of leaves. With a diminished number of leaves, the rose can’t produce the same amount of food for itself. Give the rose a boost with a fertilizer application at this time, and be sure to give it sufficient water during the dry summer.

We sell Rosa ‘Blaze’ in a variety of sizes to suit every application. We even supply completely trellised roses that have been trained for you.


Living Christmas Trees

Picea omorika - Serbian Spruce
Picea omorika – Serbian Spruce

Surfing Hydrangea Nursery has always been proud to offer a selection of living Christmas trees for sale. This year, we have some great potted Balsam Fir and Norway Spruce trees along with an assortment of other interesting varieties. They are easy to handle — no tree stand required! They are much easier to keep hydrated – making them less of a fire hazard than a traditional cut tree. And when you are finished enjoying them inside, you can even plant them in your garden!

There are a few tips to keep in mind if you would like to plant your Christmas tree outside after the Holidays:

  • Consider digging the planting hole when you take the tree home, then it will be ready and waiting when the time comes.
  • Spray the tree with an anti-desiccant like Wiltpruf before taking it indoors. This will minimize damage to the needles from hot dry indoor conditions.
  • Remember the pot has drainage holes. Place the tree on a large indoor plant saucer to collect excess water as it runs out.
  • Keep the tree well-watered when it is inside. The pot should never dry out completely.
  • If you don’t have to, avoid electric lights. The warm bulbs can speed desiccation of the needles. Or, only light the tree for short periods in the evening when you can enjoy the effect the most.
  • Minimize the amount of time the tree spends inside. Evergreen trees are not suited to thriving in normal indoor conditions. Ideally, no more than a week to ten days.
  • Re-acclimatize the tree to the cold after its been in the living room. Try putting it in an un-heated garage for a few days. Then, move it outside during the day and back to the garage at night for another few days.
  • Plant the tree as soon as you can. We often have a spell of warm weather in winter and the ground doesn’t ever seem to freeze for more than a week, so you should be able to find an opportunity in January.


Decorating with Seasonal Greenery and Berries

Christmas swag on door-1Not every door calls for a wreath. One of the fastest ways to create a decoration for a door is by bunching greens and berries together into swags. This example has Blue Juniper, Variegated Boxwood, Winter berry, Green Boxwood, Golden Thread leaf Cedar and Weeping Alaskan Cedar. We used zip ties to create small bunches of each variety, then zipped them together in contrasting rows. Once secure, we made a loop of wire for hanging and tied a bow with twine.


Plant Your Seasonal Greenery

Professional landscapers and home owners alike, often buy branches of greenery and berries to decorate Island homes for the holidays. The variety of items available commercially is varied, but can become expensive if you have a lot of decorating to do.

If you have some room, why not consider growing your own? We offer a huge variety of evergreen trees and shrubs at the Nursery for sale. Leyland Cypress, Cedar, Pine, Juniper, Fir and Spruce trees make a great addition to Nantucket landscapes. Fortunately, all of these trees can use a little pruning from time to time to keep a neat, dense habit. Why not do your pruning now and enjoy the branches? Evergreens are well on their way to full dormancy, so have no fear, borrow as many branches as you need, while maintaining a balanced tree.

While you’re at it, consider adding some plants with red berries, as well. Holly is the perfect combination of lustrous green foliage and deep-red berries. Another great plant for berries is Winter berry.  Plant winter berry in front of larger evergreen trees in the garden.  The green backdrop shows off the red berries in plantings just as when it is cut and made into garlands, wreaths and swags.

Greens and Berry Display


Over-Wintering Dahlias

Butterfly on DahliaOnly a short few days ago, dahlias were still blooming in Nantucket gardens. But our mild Autumn was brought to a halt last week with a sudden hard frost. Dahlias, being tropical flowers have since withered. But they’re not dead, only done for the season.

With a little work, you can save your Dahlias for next year! Dahlia tubers must be protected from freezing in order to survive the winter. Some gardeners have had success ‘leaving them where they lie’ and just covering them with an overturned nursery pot. I might not even attempt this approach in an area outside of a protected garden in town, but if you’re up for it, why not give it a try? Cut back most of the top growth and turn a nursery pot over above the plant. Keep it in place by pushing bamboo poles into the soil through the holes in the pot. If you like, add some additional insulation with straw or mulch inside the pot. The pot also keeps the newly emerging growth safe from deer and rabbits, just be sure it is in good contact with the soil.

If you are not a gambler, there is a safer way to overwinter Dahlias. Cut the  top growth back to a few inches. Gently lift the whole tuberous mass from the soil with a garden fork. You don’t want to damage the tubers in any way, so be sure to dig at least a foot from the stalk on all sides. Once its out of the ground, gently remove most of the soil with your fingers. A quick rinse with the hose will get those nooks and crannies nice and clean. Take a good look at what you have. If there are any areas of insect damage, remove them entirely with a sharp knife. Any tubers that are at all soft, can also be removed, as they are likely to rot in storage. Allow the tubers to dry out for a few days in the shade.

Label each Dahlia with its variety and the date you stored it away. Pack them in a cardboard box wrapped in newspaper or peat moss. Whatever medium you store them in, try to keep it on the dry side of damp for the duration of the winter. Put the box in a place that is cool and dry, but where the temperature will not fall below freezing. Once a month or so, open the box and check them for any sign of mold, or excessive shriveling (a little is normal). If they seem to be too dry, give them a light misting. If they are too moist, leave the box open for a day or two before storing them again.

If all goes well, you can plant them in the ground again in late May and they will give you another year of amazing flowers!


Dead Heading Hydrangeas

The once brilliant blooms on your Hydrangeas are now brown and crispy. They look especially horrible as they float above the plant on leafless stems. Is it ok to cut them off? Sure!

Flower heads that are not removed this time of year, are very likely to break off anyway and blow around the yard during winter. They will collect in the strangest places; in window wells, at the base of stone walls and most egregiously — inside your Spiraeas! Spent Hydrangea blossoms are easily pruned away. Just cut above a healthy set of buds below the flower.

If you would rather not do yard work this time of year, don’t worry, there is no harm in leaving them on the plant. Actually, some gardeners feel strongly that they protect the buds at the tips of the branches. I’ve never found that to be the case on Nantucket, so I happily dead-head away.

Dead Heading Hydrangea

 


Heptacodium miconoides

Heptacodium miconoides bracts
Heptacodium miconoides bracts

One of the most interesting plants in our display garden by Somerset Road is Seven Son Flower, Heptacodium micronoides. Introduced in 1980 from China, this small tree hasn’t been in cultivation for long, but is deserving of more attention. Michael Dirr, the Woody plant guru, extols its virtues in his Manual of Woody Landscape Plants. And I say, what’s good enough for Dirr is good enough for me!

This plant takes on the habit of a small upright tree, reaching 20 or more feet in height. You wouldn’t be totally amiss to confuse it with a Crape Myrtle. But in my mind it makes a nicer specimen. The dark green ovate foliage looks beautiful during the growing season. Then, in August the entire tree is covered in panicles of small, fragrant white flowers. As the flowers fade, the pink sepals at the base of the flowers become the star. They persist for two or three weeks, often into October. When the frost causes the leaves to fall, there is still more to see. The branching structure is irregular and beautiful, especially highlighted by exfoliating bark. The white outer bark peels away contrasting beautifully with a darker bark beneath.

Planted in moist, but well drained, slightly acid soil, this plant will reward you for years to come. If you would like to see a specimen as planted, we would be happy to show you ours, thriving along Somerset Road.


What’s it Thuja?

Thuja occidentalis 'Degroot's Spire' - Degroot's Spire arborvitae
Thuja occidentalis ‘Degroot’s Spire’ – Degroot’s Spire arborvitae

Before the popularity of Leyland Cypress, Arborvitae reined supreme! In the genus Thuja (Greek for Juniper), these are graceful evergreen needled trees. They make beautiful evergreen hedges, and upright specimens.

Thuja occidentalis tends to be a tighter species with little to no taper as they increase in height.

  •  ‘Elegantissima’ is an older cultivar whose needles are tipped in yellow. They are broadly pyramidal and will grow to 15′ tall and 5′ wide.
  •  ‘Smaragd’ aka ‘Emerald Green’ is touted to be an improvement since it holds its green color better in winter, and is more columnar. This cultivar is also somewhat smaller and slower growing than ‘Elegantissima’ topping out at 12′ tall and 3′ wide.
  •  ‘Nigra’, another common cultivar is also known to hold its deep green color in winter. It is very columnar and comes in at 20′ tall and only 3′ wide.
  • ‘Degroots Spire’ is often used in applications where space is an issue, but an evergreen hedge is warranted. It grows very short branches, making it extremely columnar. Although it is said to grow 4′ wide and 15′ tall within twenty years, I expect it could be easily kept smaller with judicious pruning.

Thuja plicata and its cultivars and hybrids are known to be more deer resistant than T. Occidentalis.

  • x ‘Green Giant’ aka ‘Spring Grove’ & ‘Grovpli’, is the most prominent cultivar in this species. The common name, Giant Arborvitae, speaks to the fact that these are naturally huge trees. They grow 3-5′ a year, once established, quickly reaching a height of more than 30′ and a width of more than 12′. Keep in mind, these trees are pyramidal, and can take up a lot of room in a small yard, unless maintained consistently with trimming.

Winterberry

 

Ilex verticillata 'Winter Gold' - Winter Gold Winterberry
Ilex verticillata ‘Winter Gold’ – Winter Gold Winterberry

Now that we are firmly planted in Autumn, many deciduous plants have begun to shed their leaves. At this time of year, shrubs with showy berries really prove their worth in the landscape. One of the best for fall berries is Ilex verticillata.

Although there is a range of color in the various cultivars and hybrids, red is still the most prevalent in this species. The tips of the branches are covered in berries this time of the year. The berries cling to the twigs long after Christmas Stroll, even when cut and used to accent lying, wreaths, and planters. That’s why so many landscapers and home gardeners use it for seasonal decorating.

Winterberry loves low lying, moist, fertile areas. It will do well in part shade, but situated in full sun, it will produce the most berries. Keep in mind that these plants are dioecious, meaning male and female flowers are produced on separate plants. I order to ensure good pollination of the berry-producing females, it’s a good idea to plant at least one male for ever 20 females. That male can be located up to 50 feet away. If your new planting is on an area of the island with lots of native winterberry, you might not need to plant males, but it’s a good practice, just to hedge your bets.

The other consideration for heavy fruit-set is that most cultivars are best pollinated by different varieties. For example, the late flowering ‘Winter Red’ is best pollinated by ‘Southern Gentleman’, or ‘Apollo’ which also flowers later in the season. ‘Red Sprite’ on the other hand, is best pollinated by ‘Jim Dandy’.

NOTE:  The Polly Hill Arboretum on Martha’s Vineyard has been doing work with winterberries for a number of years.  We recently contacted them to see if they had any recommendations for good winterberries on the Cape and Islands.   ‘Winter Red’ was their cultivar of choice.