September 6, 2006

The Rainy Season Begins

Nature has a way of managing cycles. Moon cycles, daylength cycles, temperature cycles, moisture cycles, even wildfires all combine to stimulate a chemical reaction within all lifeforms to grow, to hibernate, to reproduce, to feed, and to migrate. In plants, bulbs, in this case, one set of stimuli is the arrival of a rainy season, and around our planet, this is occuring and we have no control over it.

My African veld under glass
Since a good part of my bulb collection consists of species from summer dormant, winter growing areas of the southern hemisphere, like Afica or the Middle East, our New England autumn is the time to initiate the growing season with the comencement of watering. This is a landmark event in my horticultural season - the first watering of the winter bulbs. An event which I look forward to all summer.

Pots lined up and ready to have a single, deep soaking.
It's funny, becuase so many of my friends moan and groan about the end of summer, and the death and decay that autumn brings, yet one can also look to this season as a time of growth and renewal. We become so trapped in the marketing of Fall: Pumpkins, mums, scarecrows, fall foliage, especially here in New England, that from the front lawn displays to retail displays, one is swept up in a sea of orange and brown.

But there are so many other ways to look at autumn. I enjoy both, but I also know that most people don't realize that around the world, events are happening which we simple never notice. Of course, it is spring, in the Southern Hemisphere, that's a given. But even in Turkey, and Greece, the mountain meadows are violet with autumn crocus and Colchicum species. There are forests in Italy where the ground is pink with cyclamen species, jsut starting thier growing season, and a slew of autumn flowering narcissus are starting to bud, just as we are buying Halloween candy.
We all have a choice, on what we wish to notice or celebrate. I guess, I feel fortunate to have a greenhouse, where I can capture many of these events, all which add a new dimension to Autumn, and winter, or early spring.

November, around here is not only a time of Thanksgiving,Pilgrims, grey skys and cold temperature with a bit of snow, but it is also the time when in the greenhouse, the Narcissus romiexii are in full fragrant bloom, the Nerine sarniensis Exbury hybrids are in peak display with thier pinks, and magenta blossoms, and the hundreds of pots of bulbs from all over the world are starting to bud, for a succession of bloom throughout the winter.

But this all starts this weekend, with the first watering.
All summer, during spare moments, the dormant bulbs have been carefully repotted into new growing medium, generally a fast draining mix. Pots we're washed, sterilized, and bulbs were cleaned and repotted, and topdressed with gravel, and kept dry until the first week of September.

Nerine sarniensis hybrids getting a full watering to trigger fall bloom
The trigger for the autumn growth, come not only from increased moisture, but from cooler nightime temperatures. I like to wait until the night temperatures drop into the high 50's before commence watering. A single, deep and slow soaking them occurs, with the hose, and then the pots are not rewatered until growth starts showing, in about three weeks.

This treatment applies to most of my crazy collection, including the Narcissus species from Morocco and Turkey, (N. romieuxii, N. cantabricus, etc), and all of the miniature species of Narcissus that I keep in the cold greenhouse in pots; it includes all of the Cyclamen species from Europe, and all of the South African bulbs, including collections of Albuca, Lachenalia, Romulea, Fresia species,bulbous oxalis and Nerine species, to name a few.

Random ramblings - September week 1

Ipomoea platense
This relative of the common morning glory look more like a cactus than a vine, but once it blooms, one can easliy see the resemblance. OF course, this will be entering it's dormaYeah, this is another one of those plants, known as Caudex plants, so named because of thier thickened stems, or modified roots that hold water, and which allow these Madacascar natives to survive in a near dormant a(read-dead) state for most of the year until the summer rains come. I know, you may ask "why?" but caudex and caudiciform plants are regarded as highly colelctable, just enter the word CAUDEX on eBay, and see what shows up. Crazy, we plant folk are!

The alpine house, cleaned and ready for fall
With the onset of cooler weather, and rains, I am starting to move the potted alpine collection back into the alpine house. These saxifraga did will on the stone walk that leads to the greenhouse, where I could keep an eye on them and make sure that they were watered properly all summer, and where they recived bright light, but we're somewhat protected from direct sun. I think I might be starting to get soem success in growing the encrusted Sax's, at least I am not killing as many as I did two years ago when I started with alpines!
Moving the potted alpines back to the protection of this little house, helps keep the pots more consistantly damp, but not too wet, since I plunge them in my sand beds, and since the rain can't fall on then (and soon, snow) the foliage can develop more characteristically.

Alpine Auricula enjoyed the cooler summer this year
Even though July was terrible and unseasonally hot, our weather in New England suddenly switched to fall-like cycles early in August, where the thermometer only reached 80 deg. F once. I think that my success with many of the potted alpines was aided by this fact, as well as a routine that now includes a systemic for root aphids (something which has plagued my primula) and a regimine of maintenance that includes careful fertilization. This year, in an effort to master these tough-to-grow-in-the USA auricula, I changed my soil (to a fast-draining mix comprised of 50% fired ceramic Soil Conditioner, 20% perlite, and 20% ProMix, a peat soiless mix.) TO this I add some unsterilized garden soil and compost. These are roung measurements, of course, I just pour piles of material on my potting bench, and toss well.

I also now add a fertilizer in the fall, a 0-10-10, to encourage bud formation - as the brittish growers do. So who knows, at least the fall flush of foliage looks good, and the alpine Primula allionii and P. marginata are mounding up nice and dense. The roots are so strong that some have wraped around the tags. I may have to root prune soon.

Petraeovitex bambusetorum from Thailand
If you have ever visited Bangkok, you may have seen this vine. A relative newcomer, this rare and hard-to-find vine is easy to cultivate, and is something that you most likely will be seeing more of. Although, tropical vines are not something that anyone can grow, due to space issues, this is one that will bloom if kept trained to a hoop or a trellis. In the glass house, this is the first year that I have grown it, but I am so pleased with it, that I have trained one on a pole that leads to the 16 foot cieling, and another in a large hanging basket. If you plant to try this plant (I only know of two retailers in the U.S. who carry it, Logees.com and Toptropicals, you will need to leave enough room for the blossom stems to hang, since they can hang as long at three feet down. The hanging bracts are a nice touch during the end of summer.

September 4, 2006

Clerodendron bungeii

Clerodendron bungei

Fast growing tropical plants with magnificent late summer displays like this Clerodendron bungei, were at one time, only found only in botanic gardens, or private estate conservatory's with knowledgable staffs. Today, they are becoming readily available and can either be mail ordered or found at progressive fine garden centers. Adventurous home gardeners can find these alternatives to mums and hydrangeas with a little effort. A great way is to simply pay attention the next time you visit a botanic garden, and note what they are planting in containers for seasonal display. Popular publications like gardening magazines rarely show more unusual specimins since editors prefer to deliver content that not only is easlily available, but which is somewhat familiar. Trying something that is not only new to you, but new to anyone that you know, takes a leap of faith.
Still, many of these 'temperennials', a term coined by Dan Hinkley of the landmark yet now closed Heronswood Nursery, are affordable enought to be temporary yet perennial in more tropical areas. In the north, they can be allowed to grow fast all summer, and then freeze. The gardener simply needs to replace them in the spring by either taking cuttings in the fall and carrying them over indoors or buying new ones which sometimes is just easier, and better.

Regardless, if you what something different, and cool, this are the 'it'plants. They are all rage right now for home gardenering in the know. They can be found at the trediest of garden centers. Other disposable tropical annuals like Brugmansia, tropical salvia and many other tropical plants can be grown successfully in one season, with autumn as the season where they really strut thier stuff. Basically, they are treated as annuals, but unlike most annuals, these tropical plants deliver a punch that often is not seen in the late summer. Take many of the Clerodendron clan, for example.

Purchased as rooted cuttings in April, this Clerodendron bungei, a native of China and the Himalayas, starts off as nothing specia, a four inch cutting. Three cuttings were planted in a ten gallon pot, but by June, they grew quickly to about two feet tall. The growing point was pinched out, and one the hot and humid summer weather hit in July, the plants exploded into growth.

This C. bungei presents a new perspective to the late summer terrace.

Many tropical non-vining Clerodendron species that are more shrub-like in habit can successfully be grown in a single summer cycle, with the reward being spectacular hydrangea-like heads like these that are surprisingly fragrant and attract butterflies as well.

I will cut this plant back and move it back into the greenhouse, for the winter, since it is frost tender. There, is will send up new growth in late winter, where cuttings will be taken to start the cycle over again.