A Few More Maples

Some things you grow for the wonderful leaves and others have, ummm, the best description would be green leaves. Acer griseum would be one of the latter. I probably wouldn't grow it at all if it weren't for the bark. Who need leaves when you have such wonderful peeling bark. It starts doing this as a very young tree and just gets better with age. It's true that the fall color is an exquisite scarlet, but the bark is there 12 months out of the year. This is another one that is native to China. It is difficult to propagate, and so is sometimes a bit more expensive than some of the others.
Acer japonicum, oddly enough, is not the one we call Japanese Maple - that's Acer palmatum, though most of these small maples get lumped together in the Japanese Maple category. As a group, the japonicums are pretty dependable for fall color. The picture above is just the species. There are a number of different cultivars, though not nearly as many as in the palmatums.

This one is Acer japonicum aconitifolium. It is an upright and multi-branched small tree, up to about 15 feet tall. Fall color is a flame red - scarlet with overtones of orange and purple when viewed up close, just bright when viewed from a distance. Good down to zone 5.
The flowers, below, are red and not as showy as some, but still pretty.

Most maples have flowers and some are showier than others. This Acer negundo is one of the best I know. One of our rather large ones is just covered in the spring. They don't last long (and I always hope we have frost so they don't pollinate and give me multitudinous seedlings all over the garden). These sort of remind me of a multicolored spanish moss hanging all over the tree.

The negundos are often thought of as a trash tree because the species grows wild here and does have a bad habit of seeding rather broadly. Most of the selections we have rarely, if ever, seed. I also haven't had much luck in propagating them from cuttings. This one is Acer negundo 'Elegans' which seems to be an improved version of the one just called 'Variegata'. The common name for the tree is Box Elder and it is native to North America. It seems to thrive across most the the United States and Canada and as far south as Guatamala. That's the species. Some of the variegated ones may not be quite as hardy.

Hank's favorite is the one below. Acer negundo 'Flamingo'. I do like this one, but my favorite is coming up a bit farther down. This lovely pink color is found on all new growth all season long, so, unlike so many things with nice spring color, this is green, pink and white spring, summer, and fall, until they leaves color up. It grows in zones 5-8 and is a much smaller tree than the species, rarely getting over 25 feet tall. I'm told that it's a fast grower, but ours have been here awhile and they none are over 6 feet tall yet. At 25 feet they will be spectacular. This one will grow in sun or part shade; we grow them in light shade and they seem quite content.

Acer negundo 'Kelly's Gold is, as the name says, a gold leafed form. This one is good down to zone 3. They summer color is a little more muted, maybe closer to a gold/chartreuse, but still nice a bright for a lightly shaded spot. Expect this one to reach 15 feet or so and be a tree with a nicely rounded top.

Now for my favorite. How could you not love a shrub/tree that looks like this all season long. Apparently this one is much less common. When I googled it to check on the zoning, I only got about 2000 hits, as opposed to the thousand upon thousands I got for the others - and most of them are not in English, mostly German and Polish with a smattering of Dutch. I guess this is a pretty special plant since I can't seem to find a source for it in this country. I haven't done an extensive search, but so far, no one seems to carry it. All of the others are readily available. One of the things I like best about it is that, even in the shady spot where mine grows, the leaves never get even the slightest hint of green, keeping this wonderful gold with reddish shadings coloration all season.

For those of you celebrating, have a Merry Christmas. I'll be back to writing next week (maybe sooner). Not going anywhere, but just thought I'd have a couple of relaxing days after a crazy month of making baskets, knitting hats and mittens, and stuffing dinosaurs. I have a stack of good books just waiting for me to sit still in one place for more than a few minutes.

Gaudate, gaudate! Christus est natus. Ex Maria virgine, gaudate!

Jane

Acer - The Maples

Acer barbinerveThis is a small, multistemmed tree that is native to China, North Korea and eastern Russia and was discovered in 1867 and brought to England in 1890. Like most maples, it flowers in the spring. It is hardy to zone 4 which makes it an excellent choice for those in zones too cold for Japanese Maples. Fall color is yellow.

Acer campestre 'Carnival'This maple emerges in the spring with leaves that are cream, pink and light green. The picture above is just at the end of spring and so the leaves are mostly green and white. It likes light shade, or just morning sun and a sheltered position in the garden. This is a rather new cultivar and was discovered in the Netherlands in 1989. It will eventually get to be about 10 feet tall, but it is not a fast growing tree. It is hardy to zone 5.

Acer campestre 'Postelense'
Gold/green leaves in the early spring, turning limey green for the summer. Best in light shade. Hardy to zone 4. Only 6-8 feet tall and suitable for bonsai.

Acer capillipes
Acer capillipes is one of the striped bark maples. In time it becomes a quite large tree. The bark is green with dark lengthwise stripes. New foliage is bright red, turning green. It is native to Japan throughout the HOnshy and Shikoku regions.

Acer circinatum
Acer cincinatum, commonly known as Vine Maple, is a difficult tree in this area - better suited to the west coast in places like Oregon and Washington. All other species that are related to this one are found in Asia, which some people believe gives credence to the theory of a land bridge between the continents at some time in the past. This is a tall shrub or small tree, up to 15 feet tall. Here is grows at the edge of the woods, in situations that would suit a dogwood. Fall color is mostly red, though oranges and yellows may also appear on some trees. It is hardy in zones 6-9.

Acer circinatum 'Oregon Fern'This is one of the very few cut leaf Vine Maples. Although it is lovely all summer, it is in the fall when it really shines. The picture below shows what it looked like here this fall.

Acer circinatum 'Oregon Fern' fall colors

Acer circinatum 'Sunglow'Recently a few more Vine Maple cultivars have been showing up and 'Sunglow' seems to be one of the best. During the summer, the leaves are mostly green with some red/orange/pink highlights, but the name comes from the colors of the foliage when it is coming out in the spring.

Sunglow is a perfect name...

Acer circinatum 'Sunglow' new growth
More maples next time. It's a big group and we have quite a few growing here and with everything so brown and grey outside, with the exception of the snow, it is just so nice to look at the colors of the maples on a cold December night.

A small 'funny', nothing to do with maples. We have a heated birdbath which is one of the best things we ever got for the garden, a gift from my mother a few Christmases ago. It gives the birds open water all winter when the creek is frozen. Usually they just drink, but the other morning while we were eating breakfast, there was a Mourning Dove, smack in the center of the thing, just splashing away taking a bath. The temperature was in the teens, but it didn't seem to faze the dove one bit. I thought about taking a picture, but I knew it wouldn't be there all that long and if I moved to get the camera, it would fly away, so I just enjoyed watching it. You never know what's going to be just outside the window.

Jane

Red Fall Foliage - 2010

Euonymus alata has about the brightest and best hot pink color around. Much brighter than this picture gives it credit for. The plant itself is not all that exciting most of the year, but in the fall, it certainly outdoes most everything else.

Rhododendron (azalea) arborescens gradually turns from green to reddish copper. It is only just starting in this picture and would get much better in a week or so after I took its picture.

Spirea 'Gold Flame' has pretty good fall foliage most, but not every year. Most of the spireas here seem to do a pretty good job of fall color.

This is Cornus alba 'Ivory Halo'. It is a lovely shrub dogwood with green leaf centers and white margins. In the fall the white turns to pink and gives you what you see in this picture.

Cornus kousa is pretty much just a green tree after flowering in the spring. It is not a predictable fall colorer (is that a word?) but when it does color up, it gets a wonderful shade of red, almost overshadowing the Japanese maple next to which it is planted.

Acer griseum is mostly grown for its copper colored peeling bark. You can see a picture of that in the photo gallery on my website, but its fall color is a nice red, not quite as bright as Acer triflorum, but plenty nice enough.

This last one, Acer circinatum 'Oregon Fern' has to have the best and showiest fall color of anything. I know it doesn't seem to be able to decide just which color it wants to turn for fall, but no one misses it as they walk through the garden. It is not an easy tree to grow in this climate - none of the circinatums are - but we have it in a shady, rather sheltered place, and it has done well for over 10 years now.

I know I was going to post this last Friday, but I've been held hostage by Santa's elves who forced me to finish up all of my Christmas presents, and since the last animal was stuffed this morning, I am back - hopefully to be able to keep a more regular blogging schedule, at least until spring.

Jane

Fall Foliage - Things on the Yellow Side

I've spent the last few evenings finishing up some knitted things for Christmas gifts and going through all of the pictures I took this fall to share with you all. Lots of pretty things and I've sorted them by color. Tonight I'll post the ones that are more on the yellow or gold side. The one above is a Cranberry Viburnum. The leaves can vary between yellow and this reddish color.

This one is Cercidiphylum japonicum. Not only does it have parchment yellow leaves in the fall, on warm sunny days you often get the smell of brown sugar from the leaves.

This is a little known (at least I'd never heard of it when I got the plant) called Grewia biloba. It is a small shrub, at least so far, with nice fall color after green/chartreuse leaves all summer.

The Clethras don't always have nice color in the fall, but this year all of them seem to have decided to put on a nice show. We found it rather odd around here that we had such poor fall color, at least as far as trees go; only a few maples had much color at all, but things that rarely color up just had gorgeous colors

Here is a maple, Acer vitifolium - grape leafed maple that was yellowish on it's way to being quite a bit more red. Not red in the way of most of the Japanese Maples, but definitely more red that it is in the picture above.

This is one of my favorite maples, Acer tegmentosum. It needs almost full shade and a sheltered location to thrive. Ours took quite awhile to settle in, but it is now manytimes taller than I am and has wonderfully striped, almost shiny, green, grey and white bark. Once settle in, it seems to be pretty carefree. Deep rooted so I never have to give it any water, it has green leaves and then this bright yellow in the fall.

If you want unusual fall color, this Orixa japonica is about the best you can get. The leaves turn a papery white and hold that way until a heavy frost, when they drop, every last leaf, overnight. You can see the last little bit of green showing on these, but it was getting cold and I didn't want to take a chance on missing the picture. I had walked to the back of the garden every day for at least 2 weeks waiting for the perfect picture when I took this. Sometimes you just have to settle for what you can get instead of taking a chance on getting no picture at all.

Ginkgo biloba can turn this very light yellow or a deep, lemony color. If there's an early frost, like the Orixa above, every leaf will drop overnight whether they have turned yet or not. We get good fall color on them about one in four years. Gorgeous when it happens.

Tomorrow I'll post the fall colors of those trees and shrubs that are red and orange. Way too many to post them all, but I've chosen some of the nicer ones this fall. See you tomorrow.

Jane

Rhododendrons - History

Rhododendron stewartsonian (azalea)

Rhododendron 'Mandarin Lights' (azalea)

Rhododendron 'Orchid Lights' (azalea)

Rhododendron viscosum (azalea)
I just put all of the pictures up first, since basically then have nothing to do with the text today, though I guess the others from the past 4 days didn't really either. Just wanted to give you some idea of the variety of types and colors that are out there. Here is some history. As you will see, these are just a miniscule glimpse into the world of the rhododendrons.

Until fairly recently, rhododendrons were considered to be more appropriate for large estates and the prices reflected that. Plant discoveries in Asia near the end of the 19th century and the resulting hybrids opened up the possibility that ordinary gardeners could also grow them. The British were at the forefront of this change. Species were brought from China, Japan and the fringes of the Arctic Circle, from the Himalayas, Assam and Burma.

At the time of King Charles II, only one rhododendron was in cultivation, R. hirsutum, which had been introduced into England in 1656 from the Alps, and was know as the Alpine Rose.

By 1800, there were still only 12 species known. In the middle of the 1800s, Sir Joseph Hooker brought back 5 new species from the Himalayas and Robert Fortune sent back many plants from China.

By 1900 some 300 species had come to be known, but the interior of China had yet to be explored. A group of French Catholic missionaries were the first to discover what was waiting there, but Dr. Ernest Wilson made the first systematic exploration at the turn of the 19th century. From there onwards, a flood of new discoveries poured in from successive expeditions of a great company of collectors traveling through the mountains of Asia, often among hostile inhabitants, across trackless and precipitous hills, threatened by fierce storms and floods. George Forrest and Reginald Farrer died on their expedition, but their work was carried on by Captain F. Kingdon-Ward and Dr. J.F. Rock (of peony fame) and many others. This was the golden age of plant hunting in China.

Their exploration brought us new colors, new forms and a season of flowering that extended to half a year. There were dwarf plants, suitable for rock gardens, some that reached 40 feet tall, and one with leaves a yard long.

The number of known species had thus swollen to about a thousand; no doubt yet more would have been discovered if China, on becoming Communist, had not closed its borders to plant explorers (and everyone else) from the west. (my reference, printed over 50 years ago before the re-opening of the Chinese border, does not cover any newer discoveries)

We shouldn't forget, thought, that there are also rhododendrons that are native to North America, and those were also being imported into England in the 17th century. It is thought that the first deliberate hybrid was made by Michael Waterer in 1810 when he crossed Rhododendron maximum, which is native even into Canada, and Rhododendron catawbiense, from the western mountains of North Carolina. At least at the time of this book, the original specimen was still alive at Knapp Hill Nursery which he had founded. Many other hybrids followed, with the emphasis on developing plants that would be hardy in cold climates.

By the early 1900s, rhododendrons had become so easy to grow and so popular, they started replacing plants that had been popular in Victorian gardens, Laurels and Aucubas.

If you garden in northern climates, probably the most important species to you will be Rhododendron yakusimanum, originally found on the small island of Yakushima in the China Sea. Rhododendrons with this species in their genetic makeup are commonly called 'Yaks'. It is rated to survive to -5 degrees F., but it is known to survive much lower temperatures than that. For that reason, it has been used extensively in breeding for cold hardy plants. If you're looking for cold hardy rhododendrons, some varieties to look for might be Yaku Angel, Silver Bear, and Mist Maiden. Lots of them will start with 'Yaku'.

There are 2 nurseries that I would recommend highly for rhododendrons; Greer Gardens http://www.greergardens.com , whose owner Harold Greer, wrote an excellent book of the subject of rhododendrons with descriptions of hundreds of available rhododendrons and azaleas and plenty of pictures, and Rare Find Nursery http://www.rarefindnursery.com which has just a huge selection.

Enough on rhododendrons. I'll be back next week with something new. Keep warm.

Jane

Rhododendrons - Part 4

Rhododendron 'Sapho'
Another day of rhododendrons. Today I'm going to talk about some of the insects that could bother your plants. I'll repeat what I said before - we've never had any of these on our large plantings, so don't expect them and don't be scared off from growing rhododendrons because there might be something that might bother them. I just wanted people to be aware of the possibilities and how to take care of them.
Weevils are listed as a common problem. Maybe in other parts of the country. I don't know of any weevils that bother anything here. A common one on rhododendrons (to the extent that any are common) is a small black beetle about 1/4 of an inch long. They don't appear until warm weather and then they do all of their eating at night, so you may not see them, just the holes in the edges of the leaves. These won't kill your plant, just make it not quite so pretty. Orthene is rcommended to control them, but it might not be totally effective, since they may lay eggs before they start eating for the season.
Aphids may also appear on your plants. They will like to feed on tender new shoots. Orthene or Malathion will control them, but there are also other, less chemical means. A number of beneficial insects predate aphids or if the infestation is tiny, you can just pick them off or squish them.
Scale insects may appear on the bark. These suck on the bark and exude a sticky substance that turns the stems black. This is the sort of thing that also attracts aphids.

Rhododendron calendulaceum (azalea)
Caterpillars might also like to feed on newly emerging foliage. They don't seem to bother mature foliage, so as with the previous pests, you just need to keep an eye on the new growth.

Spider Mites and White Flies both feed on the undersides of the leaves. These, luckily aren't pests we see much in the garden. We have more trouble with these in the greenhouse in the winter. Spider Mites will turn the leaves a mottled brown green color. The White Flies will leave white spots where they have been sucking. Malathion will take care of both of them.

Slugs and snails can occasionally be a problem, but because of the thickness of the leaves, this isn't something you have to worry about much. Just like in hostas, those with thick leaves are not so attractive to the little slimy pests.

Rhododendron catawbiense boursault
This pretty much takes care of the planting and care of rhododendrons and azaleas. This afternoon, when I was looking for something else, I came across an older book with a chapter on the history of rhododendrons. To finish up the week, I'll share some of the more interesting parts with you tomorrow.
Jane

Rhododendrons - Part 3

As I mentioned yesterday, I can't think of any problems we have had with any of our rhododendrons and very few with our azaleas. I'll have to depend on Greer, whose book has a wealth of information. I bought the book as an aid to identifying and choosing rhododendrons and azaleas for the gardens as it is quite encyclopedic when it comes to available cultivars, but more on choosing the best plants for your garden later in the week.

There are a number of fungi who can cause you problems. If you followed the planting instructions in my last post, these shouldn't give you problems because they thrive in poorly drained soil. If you have constant standing water and the organisms get started, water splashed on the stems can cause die-back. Most fungi are most active in warm summer conditions. If fungi are a problem in your area, it is probably best to remove any fallen dead leaves and add a mulch of another kind. Bark mulch seems to have a limiting effect on these organisms. The biggest problem with the fungal diseases is that often by the time you see the symptons it's too late to do anything, especially if they have caused root rot. If you find stem die-back, you can trim out any affected branches and treat with a fungicide. If you have very hot and muggy summers, be sure to leave good air circulation around your rhododendrons when you plant them. I think half of the pruning we do here is just keeping things from growing too much into each other and cutting down on the circulating air.

Some other fungal type things you might encounter in hot humid weather are powdery mildew, which looks just like what you find on zinnias or phlox in August here. Leaf spotting from botrytis or rust is also a possibility. Often these will be a problem on injured leaves. I'll repeat again, so as not to scare anyone off from growing these gorgeous plants, I've never seen any of these things in our 10 acres of gardens where we are growing at least 50 different cultivars, and large numbers of some of those like mucronulatum and poukenense.



Rhododendron mucronulatum (azalea)

Rhododendron poukenense (azalea)

Sunburn can be a problem if the rhododendron is in too much sun. You'll see yellow leaves. These are pretty much shade loving plants, and if you see sunburn, you'll know that you need to move your rhoddy to a shadier location. If just the edges of the leaves, especially if just on one side of the plant are affected, it is probably wind burn and you need to give the plant a little bit more protections. If the burned look is on the edges of the leaves on the whole plant, it might be an overdose of fertilizer. Light green leaves usually indicate the need for more nitrogen, as in most other plants.
Tomorrow we'll go on to insect pests. Just one more pretty picture for tonight.
Jane

Rhododendron arborescens (azalea)