Make Copies Of Favorite Plants

Honeysuckle can layer naturally, and will most certainly layer if a portion of stem is simply buried or weighed down under a rock.

Where they grow wild in riparian environments, box elders, willows and cottonwoods are not as clumsy as they seem to be. As the rivers and creeks that they live so close to erode the soil around them, they often become destabilized and fall. Yet, this is actually part of their plan. If their original roots remain somewhat intact, the limbs and trunks develop new roots where they touch the ground. Eventually, these rooted limbs and trunks develop into new and separate trees.

In home gardens, a similar technique known as ‘layering’ can be employed to propagate one or a few copies of many other plants. Many sprawling vines and ground covers, such as ivy, honeysuckle, blue rug juniper and trailing rosemary, are likely to develop roots where their stems touch the ground anyway. Rooted stems need only to be found, dug and separated as new plants. Shrubbier plants need a bit more help.

Azalea, rhododendron, camellia, holly and just about any plant that has low stems that can be bent downward into the soil can be propagated by layering. Redwood, elm and magnolia do not always have limbs that reach the ground, but any that do would be pleased to cooperate as well. In fact, there are only a few woody plants that do not develop roots by layering, such as some pines and most eucalypti.

A layered stem only needs to be partly buried to develop roots. The tip should protrude from the soil a few inches. A short stem may barely protrude above the soil. A layered stem of a plant that develops adventitious roots very efficiently can be as long as a few feet. A very flexible stem can easily be held down by the weight of the soil that it gets buried with. A more rigid stem may need to be held down with a rock.

Before getting buried, the stem should be cut about a third of the way through to promote development of roots. The cut should be made on the underside so that it stays open when bend downward and buried. A bit or rooting hormone powder applied to the open wound accelerates the process. It works almost like taking a cutting, but without completely separating the cutting from the parent plant right away.

Once buried, a layered stem should be watered regularly until it gets dug while dormant (or mostly dormant) the following winter. By that time, the rooted stem can be dug and pruned from the parent plant, and then planted where desired. Because it takes a few months for enough roots to develop, layering should be done in spring.

Iris Blooms Almost Any Color

Such cheerful colors are too easy.

Iris got its name from the Greek word for rainbow, because all the colors are included. There are thousands of varieties of bearded iris alone, to display every color except only true red, true black, and perhaps true green. (However, some are convincingly red, black or green.) Then there are as many as three hundred other specie of iris to provide whatever colors that bearded iris lack.

Bearded iris are still the most popular for home gardening because they are so reliably and impressively colorful, and because they are so easy to grow and propagate by division of their spreading rhizomes. Siberian, Japanese and xiphium iris are less common types that spread slower with similar rhizomes. Japanese iris wants quite a bit of water, and is sometimes grown in garden ponds. The others, like most other rhizomatous iris, do not need much water once established. Dutch iris grows from bulbs that do not multiply, and may not even bloom after the first year.

Iris flowers are so distinctive because of their unique symmetry of six paired and fused ‘halves’ that form a triad  of ‘falls’ and ‘standards’. The ‘falls’ are the parts that hang downward. The ‘standards’ that stand upright above are the true flower petals. As if the range of colors were not enough, the falls and standards are very often colored very differently from each other, and adorned with stripes, margins, spots or blotches. Many specie have fragrant flowers. Each flower stalk supports multiple flowers. Some carry quite a few flowers!

Some types of iris are so resilient to neglect that they naturalize and grow wild in abandoned gardens. Bearded iris are more appealing and bloom better with somewhat regular watering, but can survive with only very minimal watering once established. Some iris multiply so freely that they get divided after bloom, and shared with any of the neighbors who will take them. Newly divided rhizomes should be planted laying flat, with the upper surfaces at the surface of the soil.

Six on Saturday: Schwedler Maple

Norway maple is aggressively invasive in the Pacific Northwest and the northeastern quadrant of America. It is no problem here though, and is actually rare. Schwedler maple is a cultivar of Norway maple that used to be more popular as a street tree in San Jose. I had been trying to grow copies for years. Besides propagating by cutting, I also tried grafting.

1. Double white angel’s trumpet is irrelevant to Schwedler maple. It belonged with the Six for last week, but with the addition of the picture of Rhody, did not fit. Omission of Rhody’s picture would have been unacceptable. The parent plant lives at the Santa Cruz Civic Auditorium. The piece in this picture is a pruning scrap that became more new cuttings. Bloom is very fragrant!

2. Scion wood looks like a bunch of bare twigs because that is precisely what it is. This is an important bunch of bare twigs for me. It is from an elderly tree that I met in the summer of 1976.

3. The usual suspects. Norway maple is notoriously invasive elsewhere. The few cultivars that live here are both rare and seemingly sterile. However, one noncultivar tree seeded these five.

4. High bud grafting is not my style, but was likely easier on the thinner portions of trunks five and a half feet up. Besides, the straight trunks were too perfect to waste. It will look silly later.

5. Cleft grafting was also an easier option to more typical budding. Besides, I do not trust budding with such fat buds and such thin bark. I could not find rubbers, so used elastic from masks.

6. Rhody is about as relevant to Schwedler maple as the double white angel’s trumpet. Nonetheless, he is always the main attraction of my Six on Saturday. He is as uncooperative as always.

This is the link for Six on Saturday, for anyone else who would like to participate:

Dividing Perennials Equates To Multiplying

Yuccas can get divided after bloom.

This seems like bad algebra. Horticulturally, dividing and multiplying really are the same. Division is the separation of crowded perennials into smaller but more numerous portions. It multiplies the number of individual plants. The smaller portions perform better than they did while crowded. Division is both a method of vegetative (clonal) propagation, and a form of healthy social distancing.

Many perennials are ready for dividing about now. They finished blooming through spring or summer, and are going dormant for winter. Some defoliate. Division is not so disruptive to them while they rest. Cool and damp weather keeps them hydrated. They can disperse roots and resume growth as winter ends, as if nothing ever happened. They should bloom right on schedule next year.

The most popular perennials grow for many years before getting overgrown enough to benefit from division. Some may technically never need dividing. They manage to perform adequately even as dense thicket growth. For some, division is primarily for propagation. Only a few perennials appreciate annual division. Perennials that bloom in autumn or winter prefer division in early spring.

Pigsqueak will bloom later in winter. Dividing it now with other perennials would inhibit and retard the blooming process. It will be ready for dividing before winter ends, so can settle in with the last winter and spring rain. The same applies to Japanese anemone, which might still be blooming now. Dividing these two perennials is typically for propagation or containment, rather than crowding.

Lily of the Nile and African iris do not need dividing often, but when they do, it can be a major chore. For moderate crowding, it is relatively easy to pluck many individual shoots without disturbing remaining shoots. However, it is typically more practical to dig bulky colonies, divide them into individual shoots, and then plant the shoots. African iris shoots work best in groups of five to twelve.

Lily of the Nile, with dividing earlier than later, disperses roots in winter, to bloom for summer.

Six on Saturday: Suburbia II

As I said last week, the Santa Clara Valley is the best place in the entire Universe for horticulture. That is where these pictures came from. Although I planted only the Ilex aquifolium of the second picture, I collected all six of these plants from various sources over the years. They have been quite happy here. I will now be taking more copies or originals of all but Ilex aquifolium.

1. Juniperus virginiana – is my favorite this week. I know it is uninteresting to those who are familiar with it, but it happens to be one of only a few that I brought from Newalla in Oklahoma.P00808-1

2. Ilex aquifolium – is the only one this week that I actually purchased from a nursery, while in school in San Luis Obispo in the late 1980s. It is uncommon (and unpopular) here. I still dig it.P00808-2

3. Viola odorata – came from Santa Clara while I was in high school. (I thought) I wanted it because it blooms white. It is not very pretty, but I can not get rid of it. Violets should be ‘violet’.P00808-3

4. Pelargonium hortorum – is not the original that I found in a compost pile in Montara in about 1980, but is very likely the same ‘unimproved’ species or whatever it is. I found it downtown.P00808-4

5. Agapanthus orientalis – from Watsonville in 1992, is one of my two favorite agapanthus; because it is white, but is otherwise identical to my original blue agapanthus from the late 1970s.P00808-5

6. Amaryllis belladonna – came from Hoot Owl Creek in Oklahoma. It lived in the same garden with my Iris pallida! I know it is no more interesting that these others here, but it has history!P00808-6

This is the link for Six on Saturday, for anyone else who would like to participate:

Sole Survivor

One is the loneliest number. (It is in the middle of the far edge of the flat.)

By now, I can safely assume that any of the various old seed that were sown late last February that have not yet germinated are not likely to do so. They were all so old that I knew at the time that their viability was questionable. Nonetheless, I could not discard them without confirming that they were no longer viable. Four months later, this empty flat just about confirms it.

So far, the sole survivor is a seedling of a California fan palm, Washingtonia filifera. It looks silly all alone in the otherwise empty flat. Yet, even if no other seedlings germinate, the effort will have been worth this dinky palm seedling. California fan palm happens to be my favorite palm; but I would have been just as pleased with something that is not a favorite.

This little seedling is still too young to be pulled and canned. It will therefore wait and grow in the flat for now, and perhaps until autumn. I still hope that other seed will germinate during that time. Even if they do not, the empty flat will get set aside where it will continue to be irrigated as needed until late next spring. Viable but old seed may be unusually slow to germinate.

I can not help but wonder if some of the seed did not get enough chill after they were sown late in February. Maple, ash, elm, birch and arborvitae might require more of a chill through more of winter to be convinced that the warm weather afterward really is spring. I am not quite ready to give up on them yet.

There are still many more very old seed to sow this autumn. For most, I do not expect germination to be any better than it was for this previous batch.

This little California fan palm seedling certainly seems determined to survive.

Succulents Know Recycling and DIY

Scraps of succulents can mix nicely.

There are all sorts of succulent plants, ranging from finely textured small stonecrops to huge suguaro cactus. Because aloes and agaves are succulents, the closely related yuccas, such as Joshua tree and Spanish bayonet, are commonly considered to be succulents as well. Even begonias and impatiens could be considered to be succulents.

Succulent plants are some of the most distinctive plants available. Foliage can be various shades of green, as well as yellow, red, blue, orange, purplish, gray, bronze, nearly black or variegated. Leaves may be thick and fleshy like those of jade plants, or thin and neatly arranged in tight rosettes like those of aeoniums. Cacti have no real foliage, but some have flashy flowers.

Except for the larger sorts of cacti and some yucca, most succulents are very easy to propagate. Jade plants and iceplants grow very easily from stems simply stuck wherever new plants are desired. Aloes and hen-and-chicks grow just as easily from pups (sideshoots) separated from parent plants. Technically, even leaves can be rooted, and will eventually grow into new plants.

Because scraps from pruning can be used as cuttings, there is rarely any need to actually take cuttings from desirable growth. Where more Hottentot fig (freeway iceplant) is needed on a freeway, it simply gets ‘plugged’ (as cuttings) from scraps of debris from where established growth needs to be cut back to an edge. There is much more debris than can be used!

Pots of mixed succulents are ridiculously easy to grow simply be filling pots with potting soil, and then plugging bits of various succulents. All sorts of contrasting colors and forms can be mixed. As plants grow, those that dominate can either be pruned back, or given more space by removing slower plants. The removed plants need not be wasted, but can be plugged somewhere else.

Small succulents are just as easy to plug into informal walls of stacked stone or broken concrete. Some small succulents actually stabilize loose stone. Their docile and finely textured roots are not likely to do any damage.

Cultivar Is A Cultivated Variety

Most cultivars need to be cloned.

A plant ‘variety’ is a group within a species that exhibits distinguishing characteristics. A ‘cultivar’ is simply a cultivated variety. The first five letters of ‘cultivated’ merged with the first three letters of ‘variety’ to form the word ‘cultivar’. A variety should be self perpetuating to some degree, and may be naturally occurring. A cultivar perpetuates by unnatural means, and would go extinct otherwise.

Of course, the distinction between variety and cultivar is not always so obvious. Varieties of nasturtium were selected from plants that displayed desirable qualities. Seed of these varieties grows into plants that display the same qualities. However, without continued selection, some varieties eventually revert to a more feral state in only a few generation. They are not truly self perpetuating.

Most hybrid tomatoes are unable to perpetuate themselves naturally. Their seed is either not viable, or is very genetically variable. Genetically variable seed grows into plants that are very unlikely to produce fruit that is comparable to that which produced their own seed. Nonetheless, hybrid tomatoes grown from original (primary generation) seed are generally varieties rather than cultivars.

The distinction might be that they grow from seed. A plant that is cloned rather than grown from seed is a cultivar. Cloned plants can be grown from cutting, layering or grafting onto understock, but are genetically identical to the original. Some rare camellias grown now are genetically identical copies of original cultivars that were developed centuries ago. Their seed would not be the same.

Some cultivars developed from selective breeding. Others were random but appealingly distinctive plants in the wild or even in landscapes. Many originated as ‘sports’, which are mutant growths of otherwise normal plants. For example, some plants, on rare occasion, produce stems with variegated foliage. Cuttings taken from such variegated stems became popular variegated cultivars.

Seed from a variegated cultivar is very unlikely to produce more variegated plants.

Six on Saturday: TWIGS!


The Belmont Rooster posted pictures of red mulberry that really got my attention back on February 15. The trees are native on his farm, but not here. I only remember them as decoy trees that provided berries to distract birds from other fruit as it ripened in the orchards. Of course, those that I remember were planted. I neglected to get seed or cuttings from them while in Oklahoma. I have been craving them since.

1. $8.85! The Belmont Rooster spent some major funds to get this package to me. It must be important. I already know it is very important to me! I have been wanting this for seven years. P00411-1

2. TWIGS! I got two bundles of twigs! These are not just any twigs though. They are from red mulberry, Morus rubra. One bundle is from a female tree. The other is from a male pollinator.P00411-2

3. Cuttings were processed from the twigs. There are a dozen female cuttings, and sixteen male cuttings. These are male. I was informed earlier that the female twigs were starting to foliate.P00411-3

4. Plugged cuttings are not much to look at. Rooting hormone was applied, but is not visible on the bottom ends. Only a few popping buds are barely visible in the female cuttings to the right.P00411-4

5. White mulberry was the only mulberry that I was growing here. I got the cuttings for it from a client’s tree. I do not know what cultivar it is. I have not been very impressed with it so far.P00411-5

6. The Belmont Rooster sent these cuttings from Missouri, just to the left of the center of this picture. All of Missouri is within the native range of red mulberry, which is designated by green.P00411-6

This is the link for Six on Saturday, for anyone else who would like to participate: