Bad Date

P00712-1
No one likes a bad date.

Date orchards that were displaced by the expansion of urban sprawl around Las Vegas in the 1990s were the source of the many recycled mature date palms that briefly became popular for large scale landscapes at the time. Most of the trees within the orchards were female, with only a few male pollinators. (Pollinators can live remotely, where they provide pollen for dusting.)

Male trees were undesirable anyway, at least in conjunction with female trees. They are taller and lankier, with less pendulous foliage, so are less visually appealing. More importantly, they pollinate female flowers so that they make fruit. Of course, in orchards, fruit is very important. In landscapes, it is just a mess. Without male pollinators, female trees produce no messy fruit.

Consequently, most male trees were not recycled. Some were installed singly, or in exclusively male colonies, in landscapes that were reasonably isolated from female trees. After decades of dutiful service, this is how they were retired, . . . or not.

During the brief date palm fad, a colony of exclusively female date palms at a mall near here produced a minor crop of dates during its second year after installation. It was not a major mess, but it was perplexing. Eventually, someone realized that a single relatively small male date palm lived just outside of the landscaped areas. It likely grew there from seed as a curb mongrel.

Even though the male tree was too remote to pollinate the female trees sufficiently for a major mess, it was removed. It was not much bigger than the short and clumping date palm pictured above. This tree seems to be a curb mongrel as well, since it was not likely planted there purposely. Furthermore, it will also likely need to be removed. It is too close to the building behind.

Stinky Flowers Serve Their Purpose

00610thumb
Some beetles like stinky flowers too.

From a human perspective, flowers should not be stinky. They should be pretty and colorful, and perhaps delightfully fragrant. Many flowers in landscapes and home gardens actually are. After all, they are grown for their appealing bloom. Many plants that provide only foliage produce wind pollinated flowers. They are not particularly pretty, colorful or delightfully fragrant, but not stinky either.

Flowers do what they must to pollinate each other. Since they are inanimate, they rely on pollinators or wind to disperse their pollen. Those that rely exclusively on wind produce an abundance of very fine pollen, but waste no effort on attracting pollinators. All other flowers use customized combinations of colors, patterns, textures, fragrances and flavors to attract their preferred pollinators.

There are all sorts of pollinators. Bees are the most famous. There are many other insects too. Hummingbirds and butterflies are very popular. Bats do their work at night while no one is watching. Of all the pollinators though, flies are likely the least popular. Many of the flowers that produce fragrance to attract them are not exactly popular either. Alas, fly pollinated flowers are stinky flowers.

Stinky flowers are naturally uncommon. Apparently, not many flowers want to rely on flies. Stinky flowers are even more uncommon in home gardens and landscapes, for the obvious reason. Paw paw and carob production relies on stinky flowers. A few of the various arums grown for dramatic bloom are stinky too. Philodendron bloom is quite stinky, but very rare among foliar houseplants.

Pear and hawthorn do not rely on flies, so are only incidentally and mildly stinky.

Fortunately, stinky flowers are not often a problem. Paw paw trees are rare here. Carob trees bloom somewhat briefly. If philodendrons bloom at all, they produce only a few flowers which can get pruned off. Regardless, fragrances of stinky flowers are generally not as strong as appealing floral fragrances. They neither disperse as efficiently, nor linger as long. Some are too faint to offend.

Horridculture – Stinky Flowers

P00527-1
Rhody was not impressed, and he is an expert on fragrance.

Dracunculus vulgaris – dragon lily. It was featured in the gardening column for next week, both as an illustration for the main topic, and as the ‘highlight’ species. It is as unappealing as the name and the pictures suggest, but it sure is interesting. It has several more equally unappealing common names. We know it as ‘death arum’ because that is the first name we came up with.

Besides, it smells like death. Yes, it stinks. It does so to attract flies for pollination. Actually, it attracts quite a few annoying insects. I can not explain why, but insects who congregate around stinky flowers are as unappealing as the fragrance that draws them. They are certainly very different from the appealing bees and butterflies who pollinate flowers with appealing fragrance.

The first of these death arums mysteriously appeared in the garden of a colleague several years ago, and promptly multiplied by both seed and disbursement of tubers. There are now a few expansive colonies that continue to expand. Cutting down the foliage does not slow them down much. The fragrance, which is not too bad individually, is getting to be bothersome collectively.

My colleague brought me one of the tubers to confirm the identity. I got a picture of it since it was here, but then did not know what to do with it. I did not want to toss it aside into the forest like I do with so much other greenwaste. It could have grown into a problem. I did not want to discard it either, since it was viable and healthy. So, I canned it and put it aside in the nursery.

This is the result. It is not as stinky as I expected it to be. I still do not know what to do with it.

P00527-2
These unidentified beetles that I had never noticed here before arrived promptly for the stinky bloom.

 

 

 

Good Looks Are Not Everything

00311
Less color can mean more fragrance.

More flowers bloom as winter becomes early spring than at any other time of year. For many flowers, bloom is significantly accelerated this year because winter was so very warm. Flowering cherry, purple leaf plum and most of the stone fruit trees (such as almond, cherry, apricot, nectarine, peach, plum, prune and all their various hybrids) have already bloomed.

Color is what gets noticed first. After all, that is what all the flashy colors are intended for, to get the attention of pollinators. Yet, there is more to the indirect mating strategies of flowers than color. Because flowers lack the mobility to pollinate each other, they do what they must to attract others to disperse their pollen for them. Some use fragrance.

Generally, flowers prefer one tactic or the other. This is why the most colorful flowers lack fragrance, and the most fragrant lack color. Gardenia (which is not easy to grow locally), star jasmine, honeysuckle, Pittosporum tobira, Pittosporum undulatum and night blooming jasmine are not exactly colorful while blooming. The powerfully fragrant flowers of sweet osmanthus and sweet box barely get noticed.

Pink jasmine and mock orange (Philadelphus spp.) are flashier, only because their blooms are so profuse. Southern magnolia has spectacularly big flowers, but they are mostly obscured by dense foliage high above view. Cereus cactus and moon flower are likewise spectacular, but bloom at night to attract nocturnal moths for pollination.

Only a few flowers are both colorful and fragrant. Lilac and wisteria are among the more familiar. Both bloom early in spring, with a similar color range of lavender, blue, pink and white. Lilac is shrubby. Wisteria is an aggressive vine. ‘Charles Grimaldi’ angel’s trumpet is a big shrubby perennial that blooms rich yellow, but may only be fragrant at sundown.

Freesia, hyacinth, lily and bearded iris are flashy and fragrant flowers grown from bulbs, although hyacinth and most lilies rarely bloom a second year, and many lilies and bearded iris lack fragrance. Sweet alyssum is a mildly fragrant annual that blooms white, pink or lavender.

Blue Princess and Blue Prince Holly

61207It is about time that someone reintroduced this technique! Blue Princess holly is now available together in the same pot as its male pollinator, Blue Prince holly (Ilex x meserveae ‘Blue Princess’ and ‘Blue Prince’). With careful pruning to prevent one from crowding out the other, both can coexist and provide profuse, bright red berries every winter, indefinitely. As the plants grow, their main trunks will eventually graft together.

Blue Princess holly is purported to be the shrubbier of the two. Blue Prince might be a bit more compact, and might grow a bit slower. Both eventually get about seven feet tall and nearly as broad, with remarkably glossy evergreen foliage. Their rather wavy leaves have sharply pointed teeth. Fortunately, their teeth are not quite as sharp as those of traditional English holly, which happens to be one of their mutual parents.

If possible, it might be helpful to identify the two cultivars of holly in a mixed planting, and label them so that neither one nor the other gets pruned out. Blue Prince will be the plant that produces no berries. Of course, with selective pruning ‘Blue Prince’ can be confined and subordinated to the showier ‘Blue Princess’. Individual ‘Blue Princess’ holly plants are better for hedges, with separate ‘Blue Prince’ plants nearby.

The Secret Affairs Of Flowers

61207thumbThere are some things about plants that we might be better off not knowing about. For instance, their idea of sex is even weirder than that of humans! Generally, flowers of ‘monoecious’ plants have male parts and female parts that do what they must to produce seed, which is often contained in some sort of fruit structure. Some plants can pollinate themselves. Ick! Others require separate but compatible pollinators.

Some plants bloom with both but separate male and female flowers. Female pine cones that produce seed are very different from the male pine flowers that produce pollen. Female flowers of spruce and several other conifers bloom higher in the canopy than male flowers. This promotes better cross pollination, since pollen must be blown upwardly but relatively randomly to the cones instead of simply falling from above.

Dioecious plants might seem less . . . weird. They actually have separate genders. Some are female. Some are male. Female plants require pollination from male plants in order to produce seed and fruit, though some can provide a few of their own male flowers if they sense a lack of males in the neighborhood. Ick again! There are certain advantages to every method of pollination, whether it makes sense to us or not.

One advantage of dioecious plants that does make sense to us is that messy fruit can be prevented by growing one gender or the other. Modern cultivars of Chinese pistache and maidenhair tree (gingko) are male, so can not produce the messy fruit that older trees are notorious for. Female date palms recycled from old date orchards are unable to produce dates without the male pollinators that do not get recycled.

However, this is a disadvantage if holly can not make berries because it lacks pollinators. Decades ago, scions (stems) of male holly were grafted onto female plants. Alternatively, male plants were sold along with female plants.