Zinnia

81121The same cooling weather that is initiating fall color is what finishes the zinnias that bloomed so colorfully through summer. Like tomatoes, they can stay out in the garden until they succumb frost if they continue to perform, and if the space they occupy is not needed for something else. There should be no guilt with replacing them sooner. After all, they are technically warm season annuals.

Some of the more popular types of zinnias are identified as Zinnia elegans or Zinnia violacea. Most are known merely by their variety name. They have been bred so extensively than it is difficult to assign any of them to particular species. Most are susceptible to mildew if crowded or watered from above. They want full sun exposure and rich soil. Seed can be sown immediately after frost.

Zinnias are crazily variable. Some get more than three feet tall. Others are less than a foot tall. They can bloom in every color except blue. Some resemble other types of daisies, with distended centers. Others are as fluffy as African marigolds. Some bloom with small but profuse flowers. Others have fewer but bigger flowers that are wider than three inches. Most are excellent cut flowers.

Heavenly Bamboo

51111Good old-fashioned Heavenly bamboo, Nandina domestica, which can almost reach the eaves, can be difficult to obtain nowadays. More compact modern cultivars do not get much more than six feet tall, and some stay less than three feet tall. Foliage is airier in partial shade, but more colorful where more exposed.

As it begins to emerge in spring, new foliage is pinkish or reddish before greening. It slowly bronzes by autumn. Some cultivars turn ruddy or orangish, or even burgundy. Individual leaves are actually quite large, but are divided into many small, diamond shaped leaflets. Some cultivars have very narrow leaflets. Tiny white flowers bloom through summer. Bright red berries ripen through autumn.

Although unrelated, Heavenly bamboo grows like bamboo, with vertical canes developing from creeping rhizomes. Overgrown or deteriorating canes should be cut to the ground as they get replaced by newer canes. Otherwise, they become top-heavy and inhibit development of new canes. Foliage should not be shorn, since it is not much to look at without its naturally intricate texture.

German Primrose

81114Just like African marigold that was featured earlier is actually Mexican, German primrose, Primula obconica, is actually Chinese. As odd as it is, the common name is an improvement from the former name of ‘poison primrose’, which was derived from the potentially irritating sap of the unimproved species before it was bred to be less toxic, as well as more colorful and prolific in bloom.

Here where winters are mild, German primrose is a short term perennial that is mostly grown as a cool season annual. Most of us do not bother to keep them alive as their foliage deteriorates in warm spring and summer weather. It is easier to plant new ones next autumn. They want rich soil and regular watering until rainy weather takes over. Deadheading promotes subsequent bloom.

Foliage should not get much higher than six inches. Flowers stand a few inches higher, and can get almost as high as a foot. Individual flowers can be as wide as an inch, and they bloom with several others in domed trusses that might be a few inches wide. Bloom can be white or pastel hues of pink, lavender, blue, peachy orange, salmon, rose or soft maroon, some with white edges.

Argyle Apple

51104What an odd name. It sure sounds interesting, like some sort of exotic fruit tree. Alas; argyle apple is a eucalyptus; to be specific, Eucalyptus cinerea. Compared to most other eucalypti, it stays rather low. It barely gets as tall as a two story house, even if it gets broad enough to shade most of the backyard. The rusty brown bark becomes roughly furrowed. The irregular branch structure can be quite sculptural.

The main attraction of argyle apple is the aromatic silvery foliage. Young trees are outfitted with circular juvenile leaves that are attached directly to the stems without petioles (leaf stalks). Lanceolate adult leaves are as silvery as juvenile foliage is. (Juvenile foliage of most other eucalypti is more colorful than adult foliage is.) Aggressive pruning of small trees keeps foliage juvenile for a long time.

Actually, those who know how to work with it might pollard or coppice argyle apple. Pollarding eliminates all foliated stems at the end of winter, but for the rest of the year, allows vigorous arching canes of very silvery juvenile foliage to spread outward from a few stout limbs on top of a trunk. Coppicing allows the same sort of growth from stumps just above grade.

African Marigold

81107French Marigold might have been a more appropriate choice. It is the official flower of Dia de los Muertos on November 2. Some might say that the bigger and bolder African marigold, Tagetes erecta, is just as official. Both are Mexican, but as the names imply, most varieties of French marigold were developed in France, and most varieties of African marigold were developed in Africa.

Both African and French marigolds are warm season or autumn annuals that exhibit a similar range of floral colors that contrast nicely against their rich green aromatic foliage, but they are not much more similar than that. African marigold can get almost three feet high and two feet wide. Its bigger pom pom flowers tend to be solid colors rather than mixed; and vanilla white, although unpopular, is not rare. Bright yellow and bright orange are the most familiar. Rusty red is the third most popular color.

African marigold wants rich and well drained soil in sunny exposures. It gets lanky, blooms less, and is more likely to mildew where partly shaded. It should be watered regularly and early in the day. Flowers can mold if they stay damp for too long. Deadheading, which is the removal of deteriorating flowers, promotes continued bloom. Occasional application of fertilizer might also help.

Carpet Rose

51028They compare to more traditional roses like instant coffee compares to real coffee. They are too easy and cheesy. However, even instant coffee can be rather good as long it is not expected to taste like the real thing. Likewise, carpet roses do not produce big and fancy flowers on long stems for cutting, but they have other attributes that are advantageous in the landscape.

The small but ridiculously abundant roses that started blooming late last spring are only now finishing. Bloom can be white, pink, red, coral, scarlet, gold (orangish yellow), yellow or white. The rich green foliage is remarkably resistant to disease, and lasts until frost. The arching stems can spread a few feet without getting much more than three feet tall. Most cultivars stay shorter. Some get quite wide.

Like other roses, carpet roses will need to be pruned back severely while dormant in late winter. Yet, they do not need to be pruned nearly as carefully. Because they grow as thickets of canes, they do not need to be thinned to only a few canes when pruned. Even if old canes do not get pruned out, they will get overwhelmed and replaced by newer canes naturally.

Dwarf Alberta Spruce

81031It is so tempting to dress up a densely conical dwarf Alberta spruce, Picea glauca ‘Conica’, as a garden gnome for Halloween. They are so symmetrical that they seem to have been shorn that way. They are too small to be classified as trees, but are not as shrubby as most shrubbery either. Their practicality is rather limited to formal situations where their strict symmetry is desirable.

Dwarf Alberta spruce is very different from the straight (not dwarf) species that can get to almost fifty feet tall. It instead grows very slowly, and stays quite small, although it can eventually reach downstairs eaves. The finely textured evergreen foliage is soft but slightly bristly. The tiny individual needles are only about half an inch long. The aroma of crushed foliage might be objectionable.

Dwarf Alberta spruce is popularly grown as a potted Christmas tree, and happens to be one of the few coniferous plants that can stay potted long enough to functions as such for a few years. In the ground, it wants rich but well drained soil. It can rot if the soil stays too damp. Red spider mite can be a potential problem. Although it likes full sun exposure, it can get roasted in hot situations.

White Pumpkin

71004thumbTheir creamy white exteriors do not reveal much about the flavor within. They looks like they might taste like vanilla, or coconut, . . . or maybe Swiss cheese. Below the white skins, white pumpkins (Curcubita pepo) have orange flesh that really tastes like other pumpkins, but maybe a bit milder, like ‘pumpkin-light’. They are popular because they look so cool, and make great jack-o-lanterns.

They take a while to mature, so pumpkin plants should get into the garden as soon as weather is warm enough for them in spring. They can be grown from seed sown directly, or from seedlings. They want rich soil, and need to be watered regularly in order to grow evenly through summer. The annual vines sprawl on the ground, producing only one or a few fruits each, finishing by first frost.

Popular varieties of white pumpkin, like ‘Cotton Candy’, ‘Lumina’, ‘Casper’ and ‘Silver Moon’ can weight more than ten pounds. Less common ‘Full Moon’ can get to be seventy-five pounds! White pumpkins makes as many edible flowers as orange pumpkins make, but not as many seeds. ‘Baby Boo’ and ‘Gooligan’ weigh less than a pound, and are only a few inches wide, so are inedible.

Chrysanthemum

51021thumbIt is impossible to fit enough information about chrysanthemums into just a few sentences. Centuries of breeding have produced too many cultivars to document. Flower color ranges through many shades and hues of yellow, orange, red, pink, bronze, cream, lavender and almost purple, as well as white. (True purple is purportedly lacking.) Many have yellow centers. The deeply lobed leaves are strongly aromatic.

Flower form is as variable as color is. Some are small domed buttons that bloom in sprays of many blooms. Others are round pom-poms. There are all sorts of daisy types. Spider mums have weirdly elongated ‘petals’, (which are actually ‘ray’ florets). Those that bloom singly are bigger than those in sprays. Some of biggest and most billowy seem to be too heavy for their own stems!

If they get what they want, chrysanthemums can be surprisingly reliable and easy to grow. They do want regular watering, regular application of fertilizer, and richly organic media, such as potting soil. In fact, they are popularly grown in pots because they prefer potting media to garden soil. Potted plants can be brought in while blooming, and then retired to the garden between bloom phases.

Bigleaf Maple

81024It is native from the extreme southern tip of Alaska to the extreme southwestern corner of California, but not many of us will see bigleaf maple, Acer macrophyllum, in our neighborhoods. It is planted only rarely, particularly where winters are mild. Relative to other maples, its roots can be more aggressive, and its shade can be darker, so is likely to interfere with lawn and other plants.

Mature trees in exposed situations can get more than fifty feet tall and quite broad. Old wild trees that compete with other trees in a forest can get three times as tall! The big palmate leaves from which the name is derived are about half a foot to a foot wide, and can get a two feet wide on the most vigorous or shaded growth. They turn a nice golden yellow in autumn, even in mild climates.

Bigleaf maple is like the sugar maple of the West. The sap can be processed into maple syrup and sugar. The wood is made into furniture and musical instruments. The very ornamental wood known as bird’s eye maple is derived from burl growth of various maple specie, particularly bigleaf maple. Bigleaf maple is uncommon in landscapes only because it is so aggressive and big.