Garden Notes

Garden Notes

Holiday Window Boxes

 

Holiday windowboxIn a recent news letter, I published this series of photos detailing how I put together a holiday window box for our sales office here at the nursery.  This design is a good jumping off point, but it’s just one take on Holiday window boxes, so, experiment!  Have fun with it!

Holiday Windowbox How To-1

Holiday Windowbox How To-2

 

 

 

 

Holiday windowbox-3Holiday Windowbox How ToHoliday windowbox-5Holiday windowbox-6






Oaks for Nantucket

Quercus bicolor - Swamp White Oak
Quercus bicolor – Swamp White Oak

There are few trees that have such a long recorded history as the Oak. And it’s no wonder, considering that oaks are one of the longest living trees in the Northern Hemisphere. Astonishingly, the “Major Oak” growing in Sherwood forest in Nottinghamshire, England is touted to be between 800 and 1000 years old! There is a long standing tradition that Robin Hood actually used the tree as a hiding place while on the run from the Sheriff of Nottingham! Isn’t that cool? Yes it is!

Most oaks prefer slightly acidic, evenly moist, average soil. They are not generally fast growing, but eventually can become very large. The species following are all considered large trees when mature, and are often planted in parks and larger landscapes off island. Luckily, as with many trees, there are cultivars that will fit into smaller gardens. Upright cultivars like ‘Fastigiata’ and Regal Prince (r) are equally hardy and perform well on Nantucket

Quercus acutissima leaf
Quercus acutissima – Sawtooth Oak leaf in fall

Sawtooth Oak, Quercus acutissima is a broadly pyramidal tree that might reach 40 to 60 feet tall on the mainland, likely somewhat shorter on Nantucket. It’s leaves don’t have a classic oak shape. They look much more like hornbeam or beech tree leaves to me. They open yellow in spring, mature to a glabrous green in summer and, in good years, will turn a clear yellow in November, before aging to tan. They are very easy to grow and resist pests and diseases. Like all oaks, they are slow to mature, and juvenile trees will tend to hold their leaves all winter. Sawtooth Oak can produce very heavy crops of acorns, and they are generally the earliest to ripen of the genus.

Swamp White Oak, Quercus bicolor, is a broad tree tree that will reach 50 to 60 feet tall on the mainland. The overall shape is a wide, round-topped crown, with a short trunk. The leaves of this species are much more recognizable; deep green, lustrous and lobed, with a grayish fuzz on the underside. Naturally occurring in moist areas with acidic soil, they are an ideal tree for a low area on your property in need of a majestic shade tree.

Quercus robur 'Fastigiata'  - Fastigiate English Oak leaf in fall
Quercus robur ‘Fastigiata’ – Fastigiate English Oak leaf in fall

English Oak, Quercus robur, is also a broad tree with a height and spread of 40 to 60 feet on the mainland.  The canopy is broad and rounded. The dark blue/green leaves of English Oak have a typical Oak-shape,  with rounded lobes.

  • Quercus robur ‘Fastigiata’ is an excellent   upright cultivar  that will grow very tall, but only 10-15 feet wide.
  • We have also stocked Regal Prince (r), which is a hybrid between English and Swamp
    White oak.  This particular variety is touted to be very tight, almost oval in habit.

How to Prune Russian Sage

Russian sage is a fantastic plant for us on Nantucket, having all the qualities we look for in a great perennial:

  • It’s hardy, overwintering easily without any special coddling needed from the gardener
  • It performs best in the lean, sandy soil that most of us have on the island.
  • It’s aromatic grey green foliage has just enough fuzz to make it very deer resistant
  • It has a long season of interest, looking great from June through October
  • It flowers for a very long time in mid to late summer, when seasonal residents are on the island.
  • Its lacy leaves, blue flowers and open habit make it quite versatile in the landscape.  It can be added to perennial gardens, makes a dramatic mass planting and pairs extremely well with ornamental grasses.

Although many of us have been taught to leave Russian sage standing and prune it in spring, I’ve also had perfect results pruning it in fall, when I cut down my spent perennials.  Just be sure to wait until it is dormant, preferably after a frost.

Objectives for pruning Russian Sage are:  Removing dead twigs, removing broken or damaged branches, stimulating strong growth from a balanced framework of stems that will flower the following summer.

Follow these steps to prune Russian Sage while dormant:

  1. Cut back all growth from the past season to healthy buds, within 6-8 inches from the soil.
  2. Remove any dead branches as well as broken or damaged wood.
  3. Remove any skinny twigs incapable of supporting strong new branches next season
  4. If possible, cut back a few of the oldest stems close to the soil, to encourage strong young shoots to replace the older ones.
Russian Sage before pruning
Russian Sage before pruning

Perovskia atriplicifolia healthy dormant buds-1

Perovskia atriplicifolia post pruning-1

 

 

Now that we know the right way to prune Russian Sage, I’ll let you in on a little secret. This plant is extremely forgiving; most landscapers on the island use the “Hair Cut” method of pruning.  Just gather up the twigs in one hand and prune them all off evenly with the other.  Or, if you prefer, take to them with your hedge trimmers!   New growth next summer will quickly cover any dead twigs remaining.


Pines

Pinus sylvestris 'Inverleith'  -  Inverleith Scot's Pine
Pinus sylvestris ‘Inverleith’ – Inverleith Scot’s Pine

As deciduous trees and shrubs begin to drop their leaves, evergreens become more and more visible around the island. There are many species of evergreen trees that grow well on Nantucket. Pine trees are one of the most widespread.

 

Eastern White Pine, Pinus strobus, Scot’s Pine, Pinus sylvestris, Pitch Pine, Pinus rigida, and Jack Pine, Pinus banksiana can all be found growing in different areas of Nantucket. The majority of pine trees seen in our forested areas are Pitch Pine.  This is a medium-sized tree that is native to eastern North America. Pitch Pines have shortish needles, in bundles of three, that are often slightly twisted. Although Pinus rigida is a sturdy tree with good salt tolerance, there are many better pines for landscape use. For this reason, it is not readily available in the trade.

We sell a variety of Pines at the nursery, however the following species are the most commonly planted today:

Austrian Pine, Pinus nigra, is much more available and often used for screening and windbreaks. They are densely pyramidal in youth, and broad, flat-topped when mature. They can reach 30-50 feet tall, inland, but will tend to remain on the shorter side close to the shore. They are often the tallest trees in a given area, due to their salt and wind tolerance. They do well in average soil as long as it is well drained and prefer not to be on automatic irrigation, once established.

Japanese Black Pine, Pinus thunbergii, is another common pine tree that we sell at the nursery. Like Austrian pine, they are tolerant of salt spray and wind and can survive coastal conditions. These trees have been widely planted on the island for years, and have become naturalized in some areas. Because this tree is not native to North America and produces viable seed, some consider it to be problematic, and it is being removed in several areas. Pinus thunbergii ‘Thunderhead’ is a highly ornamental cultivar that is worth a try. This tree is irregularly pyramidal, with long white buds that contrast well with its dark grey-green needles. More compact than the species, ‘Thunderhead’ reaches 10 to 15 feet tall in ten years with a dense habit.

Bosnian Pine, Pinus heldreichii aka leucodermis, is of increasing popularity. It may be a good alternative for gardeners that prefer not to plant Japanese Black Pine. Trees in the nursery are arguably more ornamental than Japanese Black Pine, and denser in habit. They are touted to have comparable salt and wind tolerance of Pinus nigra and thunbergii and are suitable for planting in dry soils. Several landscapers on the island have found Bosnian pine to be less likely to suffer infestation by black turpentine beetles than others.


Fruiting Apples

Malus 'Scarlet Sentinel' - Scarlet Sentinel Pole Apple
Malus ‘Scarlet Sentinel’ – Scarlet Sentinel Pole Apple blossoms

Have you ever noticed the difference between an apple you buy at Stop and Shop in June and a fresh-picked Massachusetts-grown apple in September? It’s remarkable how much better the flavor and texture is this time of year!  If you are tempted to plant your own, why not take the opportunity to sample the range of fruit that might be available to plant.

When choosing apples to grow at home there are a number of important considerations:

  • Space: An un-grafted tree grown from seed can reach 20′ tall and wide! With modern grafting techniques, however, pomologists can control the size of the tree. Dwarf and semi-dwarf trees are generally preferred for growing apples at home. Or, consider an espalier (A tree trained flat into a formal shape) these can be planted on a wall, or a post and wire system.
  • Exposure: Fruit trees need lots of sun to produce! If the spot you have selected for you tree doesn’t have full sun, its unlikely that you will get a good crop of apples.
  • Pruning: Apples require yearly pruning to produce the best crop. If you love pruning, apples are a lot of fun! It’s a good idea to follow a reference, Umass and Cornell have great extension services that have excellent websites. Take a peek at  http://www.gardening.cornell.edu/fruit/homefruit/3treefruit.pdf and www.umass.edu/fruitadvisor/pdf/RINLA2011.pdf these are both great resources for apple culture.
  • Pest & Disease issues: All fruit trees are susceptible to a myriad of pests and diseases. To limit the amount of spraying needed to produce quality fruit, always plant cultivars that are touted to be resistant to those problems.
  • Pollination: Apples are not self-pollinating. This means that in order to set fruit, more than one variety must be planted that blossom at the same time. Do your research! Make sure the varieties you chose to plant overlap their bloom period, otherwise its possible neither tree will bear fruit.
  • Harvest Time: Depending on the variety, apples will ripen and can be harvested from late August all the way until frost. Consider planting varieties that will provide fruit in succession.
  • Use: Choose varieties that suit your needs. Do you like to make apple sauce and butters? ‘McIntosh’ and varieties like it are ideal for that purpose. ‘Braeburn’ makes a great pie. ‘Jonamac’ is delicious eaten out of hand. Cider is another great way to enjoy apples, try combining varieties to create a ‘House Blend’.

We stock many apples at the nursery, and are happy to source individual varieties you might be interested in. Whether a mature tree is needed for your project or a young containerized plant is ideal, we can provide a plant that will fit the need.


Sweet Autumn Clematis

Clematis paniculata - Sweet Autumn Clematis flowers
Clematis paniculata – Sweet Autumn Clematis flowers

September on Nantucket is punctuated by a few really special plants. One of these is Clematis paniculata. Although this species of clematis does have a reputation for being somewhat aggressive, many gardeners consider it well worth the time spent pruning and tying.

Sweet Autumn Clematis bursts into growth in spring and will easily grow to cover a story-tall trellis in a season. It is beautiful trained along a fence, or up a pergola or down spout. Or let it sprawl along the ground in open areas as a ground cover. Plant it in full sun to part sun in average soil and this clematis will reward you with dark green growth all season and thousands of delicate white flowers in September. Even the soft, silvery seed heads are attractive, after the flowers fade.

Here are a few pointers to get the most out of Sweet Autumn Clematis in the Garden:

  • Cut back Sweet Autumn Clematis to within a foot of the ground each year while the plant is dormant. Unpruned stems left to mature for years will become woody and leafless. As well as being unattractive to look at, these stems will not produce new growth or flowers. Unpruned vines will only flush out at the top, producing a weird top-heavy appearance.
  • Take the time to train the clematis as it grows. Clematis do not cling with tendrils like other vines, their leaves actually twist around supports to climb. This habit requires a little tying now and then to help it cover the support neatly. If kept tight to the support, the rangy look that these plants can develop is obviated, and they take on a more stately appearance.
  • If used as a ground cover, be sure to pin or trim it around other ornamentals. These vines can quickly cover and smother adjacent plants.
  • If any seedlings appear in the garden, pull them up when they are young. The longer volunteers are left to establish the more difficult they are to remove.