Simplicity is the everlasting charm of English ivy, while other trailing or climbing plants have leaves that are bigger, smaller, rounder, or longer.
More brightly colored or uniquely shaped, but not one of them receives the enduring admiration we pay to English ivy—Hedera Helix and its varieties.
Many of these are hardy to below-zero temperatures outdoors, and all of them may have grown indoors. The best varieties for houses and greenhouses are miniature, semi-dwarf, or compact.
Hedera In Two Forms
To one who finds the ways of plants fascinating, English ivy holds more interest than just attractive foliage. For one thing, it is an evergreen that attaches itself to and climbs using aerial roots that sprout along the stems.
Hedera is dimorphic—it grows in two forms, first in a juvenile state, then as an adult.
The second stage is not reached until the plant has grown to the top of a rough-barked tree trunk or rock wall—a height of at least 10’ feet. Then it passes into adulthood.
The aerial roots cease to appear, and the ivy takes on a bushy form. The leaves change their shape, too, and clusters of dainty, white flowers are produced, usually in the fall.
English Ivy Mutation
Another remarkable thing is that most, if not all, new English ivies originate as sports or mutations of other varieties.
These appear naturally and frequently. However, if you grow ivy successfully for several years, chances are you will have the pleasure of seeing at least one branch grow partially to entirely different from the rest of the plant on which it appears. To propagate this maverick, clip it from the other plant and root as any ivy.
English ivy merits being planted lavishly in the house and greenhouse. It can grow in clay or plastic pots, with or without support, such as a trellis or totem pole.
It can be planted in redwood, wire, or other hanging baskets, and cultivate the true miniatures or semi-dwarfs in a strawberry jar.
Root plenty of cuttings in the fall to have quantities of potted ivies for use in the spring and summer window boxes.
Since late frosts won’t harm it, the ivy can be planted several weeks ahead of petunias, geraniums, and other window box plants.
Training English Ivy
The most exciting way to grow English ivy is to train it to tree form. The size and shape of the tree are entirely up to you—a tiny one of miniature ivy or an impressive tree 2’ or 3’ feet tall; the shape may be that of a globe, a pyramid, or a cone.
Here is how:
- Make a framework of one-inch chicken wire or similar material.
- Fill it with coarse sphagnum moss which has been moistened in regular strength fertilizer such as 23-21-17, then secure the base of the form in a pot of moist soil (the same mixture you use for other ivies).
- Plant-rooted cuttings of ivy at intervals all around, placing them between the pot and the base of the framework.
- Train them to cover the form; the stems may be hair pinned to the moss until they root into it.
- Give the moss a soaking often enough that it does not become completely dry at any time.
- After the tree form has been covered, routine pruning will keep it tailored to the same proportions indefinitely.
- Turn the tree every few days so that each side receives its share of light.
Growing English Ivy Indoors
Few plants grow as easily as English ivy. Its cold hardiness sets it in a superior class for growing in a window that gets chilly at night; even when humidity condenses on the windows and freezes into ice, ivy growing on the same window still thrives as never before.
Despite this enthusiastic introduction to ivy culture, there is one negative aspect to the subject: If the soil in which ivy is growing is allowed to be severely dry for more than a few days, the plant will die.
The keys to success with Hedera Helix indoors are these: Grow it in moist soil where the atmosphere is cool and humid.
Of these three, the first and last are requirements; the middle one can vary widely—comfortable room temperatures will not harm an ivy with moisture at its roots and in the air around it.
Planting English Ivy In Garden Soil Outdoors
Outdoors, we plant English ivy in good garden soil—moderately fertile, enriched with humus, and well-drained. Unfortunately, this same soil is not a good choice for potted ivy.
The best growing medium I know of for container-grown ivies is this: three parts screened sphagnum moss to one of Perl-Loam (a fine-grained form of horticultural perlite).
Ivies growing in this mixture should be fertilized once a month with regular strength houseplant fertilizer that has a ratio of nitrogen 23, phosphorus 21, and potash 17. Also, a mixture of equal parts garden loam, vermiculite, and peat moss will grow good ivy.
Another guide for what to plant ivy in: Commercial or homemade mediums that grow healthy African violets will also produce satisfactory ivy. Except when ivy has been planted recently in rich, humus soil, fertilizer applied once a month is sufficient.
Planted in a fertile soil mixture, no additional plant food is needed for several months.
As House Or Greenhouse Plants
As house or greenhouse plants, ivies do well with bright, open shade, up to several hours of full sunlight, particularly during the fall and winter.
Some varieties tolerate less light than others; some need more to induce compact growth.
When ivy receives enough light, the stems will be sturdy and the foliage a bright, healthy green. Without sufficient illumination, the spaces between the leaves will be long and spindly, and the foliage will be pale green.
Such a condition may also indicate too much heat, lack of humidity, and insufficient water in the soil.
Planting In A Container
Ivy is most likely to thrive when planted in a container that has a drainage hole. If you find it necessary to use one that does not plant the ivy in a light, airy planting medium such as Black Magic Planter Mix or the mixture of three parts screened sphagnum moss to one of Perl-Loam.
Watering English Ivies
Under average house conditions, ivies should be thoroughly doused with water at least once a week.
Set the plant in the sink or bathtub, cover the soil with a piece of polyethylene plastic, and then shower the foliage above and beneath with clean water, preferably at room temperature.
It is important to remember that a humid window in the summer may be arid whenever the weather is cold enough to necessitate using the furnace. Therefore, the hotter and drier the atmosphere, the more often ivy should be given a shower.
Controlling Pest Problems
If the upper surfaces of ivy leaves are white- or yellow-flecked, and there are tiny webs beneath them, and in the axils of the leaves, minute red spider mites are present.
I have always maintained that if English ivy is kept moist at all times and the air around it is reasonably humid, then red spiders shouldn’t present much of a problem.
However, sometimes they do not play fair, and despite seemingly perfect conditions, it is necessary to use a miticide at seven-to-ten-day intervals until there are no further signs of them.
If possible, dip the ivy in the miticide (mixed precisely according to package directions); otherwise, spray.
Brown Scale Sometimes Infests Ivy
An individual mature scale is an oblong-round tan-colored spot about an eighth of an inch long. Scale first feeds on the undersides of the leaves, but as it multiplies, the leaf undersides, tops, and stems may be covered.
A larger plant infested with scale should be dipped in a pail of malathion; a small one may be dipped in malathion, or sprayed with a house plant aerosol insecticide bomb.
44659 by Elvin Mcdonald