By Vincent LoVerme     

For most people, winter can be the longest season of the year, with one cold day after another and one snowstorm after another. January and February can drag on and on, and some years it feels as though winter is never going to end. But for those of us who garden, we have something to anticipate that makes that long stretch of winter a little more tolerable - the first flowers of the new year. Just when we think winter is never going to end, these late winter/early-spring bloomers offer proof to us that once again, winter will come to a close and spring will arrive.

The first shrub that comes to mind when thinking of winter flowers is Jasminum nudiflorum, commonly known as Winter Jasmine, which forms a broad mound of bright green trailing branches that really stands out against the dull colors of winter. In late February, early March, cheery yellow flowers begin to open and continue over several weeks. They can't help but bring a smile to a weary winter face. The shrub grows 3- to 4-feet tall and 4- to 7-feet wide with nice pinnately compound, deep green leaves throughout the season. Let the branches weep over a wall or train them onto a trellis, or given its tolerance to very poor soil conditions, mass several on a slope.

Abeliophyllum distichum is another plant that is often in flower by mid- to late-March with white or pale pink, extremely fragrant flowers, which come together to form showy racemose panicles atop arching leafless branches.  Often referred to as White Forsythia, this small multi-stemmed shrub from Korea grows to 5-feet tall by 4-feet wide and prefers full sun to light shade.  Over time it can become somewhat rangy, so it should be cut back every three to four years.           

Another terrific winter blooming shrub is Winter Honeysuckle, also known as Lonicera fragrantissima. The specific epithet refers to the tremendous sweet lemon fragrance these flowers emit. Being a deciduous shrub, the creamy white often tinged pink or red flowers are borne on bare branches in late March or early April. They are not as showy as those of many other plants in full flower but the fragrance certainly makes up for that, often perfuming across the entire yard. It grows 6- to 10-feet high and wide into an irregularly round mass of slender recurving branches good for hedging, screening, backdrops, and shrub borders. It is also very tolerant of a wide range of soil and sun conditions, is very hardy, and is non-invasive like some honeysuckles can be.

Here's a shrub you may never have heard of, because it is quite uncommon in the trade, yet very interesting - Stachyurus praecox.  If sited properly in a woodland garden setting (moist, but well drained, acidic with light shade), this shrub will perform admirably, growing 4- to 6-feet high and wide in an upright, arching habit with lustrous dark green leaves. The flowers, occurring before the leaves in 2- to 3-inch long, pendulous racemes, are small and pale yellow, putting on quite a show in late winter to early spring. Being hardy to zone 6, this Japanese native will do just fine here in southeastern Connecticut, and we will have a few for sale this spring.

When explaining the genus Mahonia to customers here at the nursery, we have a tendency to focus on the unique texture these broadleaf evergreen shrubs present. The leaves are stiff, leathery, and spiny, with a lustrous dark green color, and are often thought of as holly-like. It's one of those plants that people seem to immediately really love or really hate. The other attribute we always speak of is its ability to tolerate sites with less than ideal sun conditions. But what we so very often forget to mention are the flowers, and for this we should be ashamed. Several species of Mahonia bear incredibly showy upright racemes of flowers in varying shades of yellow, and with varying degrees of fragrance. These flowers peak in late winter to early spring and most are followed by blue-black berries during the summer. These attributes definitely make interest for all four seasons. Just be cautious of winter hardiness, as some Mahonia species are more cold tolerant than others. We carry several types including Mahonia aquifolium, M. bealei, M. japonica, M. x. media 'Winter Sun', and M. repens, an interesting groundcover type.

One of the most commonly thought of winter blooming woody plants for most people is Hamamelis or witchhazel. Witchhazels are best known for their showy and fragrant late winter, early spring blooms, which range from all shades of yellow, to oranges, and reds. But other attributes of this group of shrubs and small trees include their tremendous range of fall colors, great form, and tolerance to most environmental conditions. Some of our most favorite cultivars include Hamamelis x intermedia 'Arnold's Promise' because of its unequaled profusion of clear yellow flowers with a reddish calyx cup, which perfume with the most intense fragrance.  H. vernalis 'Purpurea' (Washington Park) is another great form with bright purple flowers and good fragrance. H. mollis 'Wisley Supreme' develops the most sweetly-scented clear yellow flowers.  H. x. intermedia 'Ruby Glow' is another great cultivar but with coppery red flowers maturing to reddish brown.  Be sure to stop and see our mature 'Ruby Glow' specimen in the Oliver gardens.  

It just so happens that my favorite genus, Viburnum, does have one reliable winter blooming form in our climate here, Viburnum x bodnantense 'Dawn'. This old hybrid between V. farreri and V. grandiflorum boasts the most intensely fragrant pink blooms, which are quite pretty but aren't nearly as showy as the fragrance is strong. This combination is certain to pull one out of the winter doldrums. In my opinion, this plant is best grown in tree form where with proper pruning it makes quite a specimen.  

Another rare tree worthy of being used more is Prunus mume, the Japanese Apricot. This small tree produces 1- to 1-1/4-inch diameter, pale rose, fragrant flowers on bright green stems in late winter. This outstanding show is followed by yellowish round apricot-like drupes in summer. We will have two unique cultivars for sale this spring; 'Kobai' with rich pinkish-red, semi-double flowers, growing to about 15- to 20-feet tall, and 'Pendula', a weeping form that grows to 10-feet with single or semi-double pale pink flowers.

Another March flowering tree is Cornus mas (Cornelian Cherry Dogwood). This small tree grows to about 20-feet and displays a profusion of yellow flowers in umbels, effective for several weeks before the leaves. The fruit that follows in July are small oblong, bright cherry-red drupes, edible, and used in making preserves. Add to this nice red fall color, and a showy, rich brown exfoliating bark, and you've got one of my favorite four season trees.  

Even though this last group of shrubs flowers a little later into early spring, they are responsible for bridging the gap between winter and spring, producing showy blooms before the leaves in April. This genus Corylopsis, also known as Winterhazel, is a member of the Witchhazel family, and is made up of several species from China, Japan, and Taiwan. All species have exceptional summer foliage, are quite versatile - preferring conditions anywhere from full sun to tolerating quite a bit of shade, wanting acidic soil but are tolerable of most types - and are plenty hardy to zone 5 and 6. The two most common forms we carry are Corylopsis pauciflora, the Buttercup Winterhazel, and Corylopsis spicata, the Spike Winterhazel.  This year we will have other rarer types that are unique and exciting as well. Corylopsis veitchiana is a unique mid-sized species with huge weeping racemes up to 3-inches in length of small buttery yellow flowers with a nice light fragrance, accompanied by bronzy new growth that matures to clean, bluish green summer foliage. Others include Corylopsis sinensis var. calvescens, also known as C. platypetala, and Corylopsis glabrescens var. gotoana. Both species produce fragrant, pale yellow flowers in 1- to 2-inch long racemes, have nice glaucous, waxy leaves during the growing season, and grow to about 8- to 10-feet. All forms would make worthy additions to any garden.

I need to be sure to mention that the flowering times stated above are the average or most typical times they peak in a normal season, but that they do vary from year to year. Prolonged periods of warm temperatures will accelerate bloom times and of course, lengthy periods of cold will delay them. For example, with the abnormally warm temperatures we've had so far this winter, I've witnessed Mahonia japonica at Olivers with flowers partially open in mid-January. And, I'm sitting here looking at the Dawn Viburnum off my back porch with its buds half swollen and ready to pop in late January. The only thing we can truly rely on being the same is succession of bloom; that is the sequence with which these plants come into flower.

The best thing about all the above-mentioned plants is that they bloom at a time when they can truly be appreciated, before the mass profusion of spring flowers commences. They bloom before all the azaleas and rhododendrons, all the lilacs, all the crabapples, and so on, and of course, before any deciduous trees have leafed out. It's like the slightest bit of color at this time of year is worth so much more than the same amount in May or June. And maybe this is because I'm in the nursery business, but it just seems as though once all these other flowers come into bloom, there's so much to appreciate and so little time to do that. I often feel as though certain plants get lost in the hubbub and I'm not able to truly spend time appreciating and enjoying them.  And of course, the other most important thing is that they come at a time when we just seem to need them the most, winter's home stretch. 

The nursery officially reopens in early March, but we're often here in February preparing for the season, so don't hesitate to stop in and see what might be in bloom. You may just discover a new off season favorite.  

Peonies That Don't Grow on Trees,
and Their Cousins: Intersectionals   

By Melanie Fox 

Rule number one: tree peonies don't grow on trees.

Rule number two: an intersectional is not some bizarre plant reproductive process I would rather not explain in detail!

Rule number three: I have promised to keep this article as short and sweet as possible given the titanic subject matter!

Rule number four: I have broken rule number three in the interest of providing complete horticultural information.

Our last newsletter featured an article on herbaceous peonies, and I talked about how peonies can become the theme of an entire border, and an object of obsession. Well, the first is a bit more difficult with tree peonies, as they grow significantly larger than their herbaceous cousins: 5-feet high by 5-feet wide, as opposed to 3-feet high and wide for many herbaceous varieties. Some plants can grow up to 10 feet high, but that's only after 50 years! However, the determined collector can showcase a good number, even on a quarter acre plot! I know this because a long-time employee of Oliver's has 12 well-established plants in her cozy Southport garden, where they form a glorious tapestry of bloom every May, making her the envy of less fortunate gardeners, like myself, who don't have any tree peonies - yet.

Tree peonies are not tree-like except for their woody stems and are much more akin to mid-size shrubs in habit. Most are grafted with faster growing cultivars coming from divisions, and plants are relatively slow growing, taking well over five years to begin to show mature size, which explains why they are a costly item.

Tree Peonies were first cultivated in China over 1,600 years ago, first as medicinal plants and later for their astounding beauty. Images of tree peonies are abundant in Chinese art, revealing the long standing reverence in which they are held. In the early 17th Century, the plant was brought from China to Japan, and the Japanese chose to cultivate them a bit differently. The Chinese continued to grow tree peonies for medicinal and horticultural sale, but access to plants was limited for political reasons, so most plants in commerce were from Japan or Europe. Today, Chinese tree peonies are available, but often Japanese plants are preferred by growers because they bloom more quickly, and tend to produce a more uniform plant, which makes them readily marketable. "What is the difference between a Japanese and Chinese tree peony?" you ask. Chinese plants tend to take longer to establish than Japanese cultivars, but are ultimately more vigorous and taller than their Japanese counterparts. Some Chinese cultivars are highly fragrant whereas Japanese plants are not. Chinese selections come from a greater number of species crosses and so they vary more in size, foliage types and flower forms. Japanese tree peonies often flower on one-year grafts and have a much less diverse gene pool, which makes them more uniform in size, leaf shape and flower form. And, they only become very vigorous when they have fully developed their own root system.

So, why buy a tree peony, right? Well, how about a shrub with good foliage, relatively slow growth rate, and gorgeous blooms three times the size of our largest roses? Sounds pretty compelling to me, and they will grow well with four to five hours of direct sunlight so you can still plant some if you have already stuffed other shrubs like roses or lilacs in all your full sun spots! But, the undisputed crowning glory of a tree peony is its flowers, although some plants have the added appeal of red or purple buds, stems and early leaves.

For me, it is not just the glorious flower, but the breathless anticipation that the appearance of that first, gorgeously-baroque, heavy bud unleashes in an unwary gardener's breast. It's nearly impossible not to stay and watch that perfect glaucous green package unfurl to reveal nature's ultimate floral surprise. It's clear to see why the Chinese closely guarded them from early European plant hunters, and one emperor declared them under imperial protection.

I smile to myself every May as I watch the spring ritual - where tree peonies effortlessly captivate new customers and continue to delight collectors. For new customers, ritual begins with a simple walk by the plants, a pause, before they resume walking, only to find their steps returning to the benches where the tree peonies sit in their unselfconscious splendor. The ritual may take up to a week, as the customer returns, worships from afar, asks questions about plant origin, size, and ease of culture, and may include an attempt to convince a skeptical spouse that space actually does exist in the yard for this truly magnificent specimen! After several visits the prospective owner gives in to the inevitable and happily loads a complacent beauty onto a cart, sometimes not precisely sure where it will go in the garden, but just that it cannot be left behind! Last year most of our tree peonies had no need to flaunt their stunning flowers to attract owners - now that's allure!

Tree peony flowers come in single or double form - some petals are very ruffled, others only slightly wavy, but all are quite impressive. The Chinese recognize eight separate flower forms: Single, Lotus, Chrysanthemum, Rose, Anemone, Crown, Globular or Silk Ball, and Proliferate. These designations are rarely used in the United States except in certain nursery catalogs. Blooms display in hues of white, red, burgundy, pink, lavender, some bi-colors, and wonderful soft yellows to coppery peaches. A mature tree peony with close to a hundred blooms, or better yet a group of them, is a sight not to be forgotten.

Culturally, tree peonies prefer a slightly alkaline, well-drained soil, and will grow in full sun to partial shade (four to five hours of direct sun, preferably morning). They shed their leaves and flowers like a deciduous shrub, and may be selectively pruned to keep their form balanced. They are long lived and can thrive for well over thirty years. Most tree peonies flower in mid-May which overlaps with mid-season herbaceous peonies, but remember: bloom times can vary by two weeks depending on extremes in weather. The flowers may take several years before they display their mature form. For example, a fully-double cultivar may produce semi-double or single flowers in the first few years. It is important to purchase your plant in bud or bloom, as images don't always accurately convey color depth and nuance.

Plants can vary in vigor so some plants will be very robust when young. These are field grown and generally harvested as 2- to 3-year old plants. Other varieties may be kept in pots after grafting and will be significantly smaller, which doesn't mean they won't catch up when planted in the garden. For example, the white tree peony, Tama Sudare, 'White Jade Tracery,' which we will carry this spring, is a highly-desirable variety, but pot grown, so the plants will be smaller. Two characteristics to consider when selecting a plant is stem strength, and how the blooms are held on the plant. These are similar to what you look for in herbaceous peonies - strong stems and flowers that are held upright for optimum viewing. Interestingly, the Chinese have some highly-desirable forms which bear weeping flowers, a trait most American breeders would try to remove.

Most of the tree peonies offered at Oliver's are the product of one American breeder, Nassos Daphnis, whose introductions are highly regarded by novices and professionals alike. Daphnis hybrids show exquisite color and balance of form, clear reflections of his long and successful career as an artist. The majority of Daphnis's introductions have names from Greek mythology or classic literature, a nod to his country of origin. The colors on some of his plants are wonderful subtle overlays which make them sometimes difficult to convey with words - for instance, a burgundy flower can have blue, red, hints of pink, and black all at once. Therefore, I strongly urge you to come see the plants themselves in the spring and judge their magic firsthand.

Intersectionals are crosses of herbaceous peonies with tree peonies. The first person who was successful at this often-attempted cross was named Toichi Itoh, so intersectionals are also called Itoh hybrids - the first was created in 1948. Itoh peonies have the best genes of both parents: dissected foliage, slightly woody stems, some fragrance, more compact stature, and abundance of blooms. Some Itoh hybrids can produce flowers for up to a month - what's not to like about that?!

Itoh hybrids stay compact, ranging from shorter cultivars like 'Border Charm' at 24-inches, to larger varieties like the classic yellow 'Bartzella' at 36-inches. Plant these in full sun, well-drained soil, and plant with slow release, high phosphate fertilizer at planting time. Itoh peonies are also very long lived like their parents, and can be divided like herbaceous peonies. Their color range is from near white to pink, lavender, red, pale to strong yellow, to coppery peach. Flowers can be single or semi-double and the petals are often streaked with another color, or will display a distinct overlay of colors. Some blooms change the longer they are open - which creates the unique look of some selections.

So yes, unless it's the luscious, soft shimmery yellow of 'Bartzella' (which is very well documented!) that you are after, you must come and see the plants. Intersectionals bloom in late May for about two to three weeks, but are capable of limited re-bloom if cut back right after the first flush of blooms. Itoh peonies also make excellent cut flowers, lasting about five days in the house ('Bartzella' and 'Kopper Kettle' are also fragrant). The first two reasons are ample enough for including these plants in your garden, but they are also quite easy to grow and have excellent foliage - a true home run plant.

Well, I hope I haven't sunk you readers with my attempt at trying to cover this subject, or had you running for your lifeboats in the first paragraph! These two incredible groups of plants have quite a bit published about them - I have really just provided you with a basic understanding of them. The main breeders of intersectional peonies in America today are Don Hollingsworth, Roger Anderson, and Donald Smith, so you can't go wrong purchasing a plant introduced by one of these three breeders. I look forward to seeing you all in the spring as yet another marvelous peony season unfolds! I'll be the one in the Oliver jacket circling and re-circling the tree peonies. See you there!

This spring, we'll be offering the following Itoh hybrid peony varieties: