Dormancy And Defoliation Are Advantageous

Hostas go dormant and defoliate for winter, and regenerate for spring.

Many plants are deciduous in autumn and winter, which means that they defoliate or die back, and then refoliate or regenerate in spring. Many others are evergreen, which simply means that they are always foliated through all seasons. What many people do not realize is that evergreen plants replace their foliage just like deciduous plants do. They just do not do it in such distinct phases of defoliation, dormancy and refoliation.

Tropical plants like cannas and some of the various begonias really have no need for formal defoliation, since they are from climates that lack winter. In the wild, they continually and systematically shed old stems as they produce new stems. Locally, they tend to shed more than they grow during late autumn and winter. The large types of begonias tend to keep their canes for so many years that it is not so obvious. Where winters are colder, cannas freeze to the ground, only to regenerate from their thick rhizomes as winter ends.

Zonal geraniums may seem rather tired this time of year for the opposite reason. They expect late autumn weather to include frost that would kill them back to the ground where they would stay relatively dormant until warmer weather after winter. Just because their foliage is instead evergreen through winter does not mean that it should be. It lingers and often becomes infested with mildew and rust (fungal diseases) that proliferate in humid autumn weather.

However, zonal geraniums need not be pruned back just yet. Even if they eventually get damaged by frost, pruning should be delayed so that the already damaged older foliage and stems can shelter the even more sensitive new growth as it emerges below. They can get cut back after frost would be likely.

Evergreen pear can get very spotty once the warm weather runs out because the same damp and cool weather that inhibits its growth also promotes proliferation of the blight that damages and discolors the foliage. The damaged foliage eventually gets replaced as new foliage emerges in spring, but will remain spotty and discolored until then. Photinia does not get as spotty, but holds blighted foliage longer into the following summer. Ivy can be temporarily damaged by a visually similar blight.

Many Perennials Want Seasonal Grooming

Where frost is not a major concern, old canna foliage can be cut back as new growth develops.

Here on the west coast, autumn and winter weather is so mild that the native coral bells are already starting to develop new foliage on top of the old foliage from this last year. Technically, they are evergreen, so the old foliage does not need to be shed; but if it is not too much to ask, some types look better with a bit of grooming.

Other perennial plants that are from climates with stronger seasons and colder winters are not quite so evergreen. Many shed all of their foliage and are completely bare for at least part of the winter. Only a few, like cyclamen, are at their best through autumn and winter.

Dried watsonia foliage should be removed now if it has not been removed already. It is not so easy to pluck off like gladiola foliage is, so it should be cut off with shears. Because new foliage for next year develops before the old foliage of this past year is completely brown, it is often necessary to cut the old a few inches above the ground in order to avoid damaging the new.

The so called ‘evergreen’ daylilies can be even messier. New foliage is rather delicate, so it is easily tattered by the removal of old foliage. The ‘deciduous’ types may seem to be less appealing because they are bare for part of autumn and winter, but are so much easier to groom by simply removing all of the deteriorating old foliage as soon as it separates easily from the roots.

Deteriorating flowers can be removed from cannas; but their lush foliage can stay until it starts to deteriorate later in winter. Even if it survives winter, it should eventually be cut to the ground as it gets replaced by new growth in spring.

The many different iris have many different personalities. Most should be groomed sometime between summer and late autumn, although Dutch iris were groomed much earlier. Bearded iris that do not get divided can be groomed simply by plucking off big old leaves to expose smaller new shoots below.

Some dahlias bloom until they get frosted. Most though, are already finished. They do not need to be cut back all at once, but can be cut back in phases as leaves and stems dry and turn brown.

Cooler Weather Is Slower Weather

Cooling weather can damage new growth.

Weather is not quite as warm as it had been. Warm days do not last quite as long as they did earlier in summer. Afterward, the longer nights get a bit cooler. Technically, autumn is only a few days from now. Although seasonal changes are mild, and a bit later here than in other regions, they eventually catch up. Plant activity has already been getting slower.

Seasonal changes keep gardening interesting. Plants that are now growing slower than earlier may need less attention. However, some need more attention, precisely because they are growing slower. Some of the work that was so important through summer should conclude until spring. Some of the work that will be important through winter begins now. 

Although evergreen, photinia and pittosporum hedges do not do much between now and next spring. If shorn too late, new growth develops slowly, and may become shabby as a result of cooler and rainier weather later. Late pruning of citrus stimulates vigorous newer growth that may be sensitive to frost through winter. Lemons are particularly susceptible.

Conversely, dormant pruning can begin as deciduous foliage starts to fall. Although most roses and fruit trees supposedly prefer to wait until winter, they may soon be too dormant to notice if pruning is a bit premature. This is partly why autumn is the season of planting. Mostly dormant plants are more resilient to discomforts than they would be while awake.

New Zealand flax, lily of the Nile, African iris and other rugged perennials are conducive to division now. They will soon be about as dormant as they get, but will want to disperse roots for winter anyway. They resume growth before winter ends, so want to be ready for it. Once rainier and cooler weather resumes, they will need no watering until next spring. 

Fertilizer should be passe soon also. Most plants consume less nutrients through cooler weather. Besides, many nutrients are less soluble, and therefore less available to plants while the weather is cool. Turf, cool season vegetables, cool season annuals, and some small palms are a few exceptions that could benefit from minor applications of fertilizers.

Seasonal Changes Keep Gardening Interesting

Oleander continues to bloom into autumn.

Gardening is work. The extent of such work is proportionate to the techniques and scale of the gardening. Substantial gardens likely need substantial work. Fruit trees, roses and vegetables need more specialized work than lawns and wildflowers. Seasonal changes demand a strict schedule. It never ends. It is ironic that so many enjoy gardening to relax. 

In some climates, gardening is less work through the harshest of winter weather. No one wants to be outside in harsh weather anyway. That is no excuse here, where the garden remains active throughout the year. Perhaps that is a disadvantage of such mild climate. Furthermore, seasonal changes, regardless of how mild or slow, are reliably continuous.

Another month of summer remains. That may seem like enough time to stay on schedule for summer gardening, and maybe take some time to relax. However, it is already time to begin preparation for autumn gardening. Gardening should progress as efficiently as the seasons do. Seasonal planning facilitates this process. It will be autumn in only a month. 

Warm season annuals and bedding plants are still in season. Most will remain in season until cool weather in autumn or perhaps the first frost. Nonetheless, cool season annuals for autumn begin to grow from seed about now. If started early enough, they will be ready for planting into the garden at the proper time to replace their warm season counterparts.

The same applies to vegetables. Many warm season vegetables can produce until frost. A last phase of corn should still have time to mature. In the meantime, some cool season vegetables can begin to grow from seed. Broccoli, cabbage and larger types can start in cell packs or flats. For direct sowing, root vegetables may need to wait for garden space.

Some of the many plants that bloom through most of summer bloom less later in summer, even though the weather remains conducive to bloom. Some prefer to divert resources to seed production as the days get shorter. Old fashioned oleander with fragrant bloom can get shabby with seeds. Modern sterile types lack fragrance, but bloom until cool weather. It is a good time to collect seed from formerly seasonal flowers.

Fertilizer Is A Seasonal Commodity

Fertilizer is about to be passe.

Fertilizer, in simple terms, helps plants grow. It provides a bit more of what growing plants crave. In some situations, it compensates for nutrient deficiencies. Fertilizer can be organic or synthetic. Various formulations serve a variety of purposes. Custom formulations appeal to plants with discriminating taste, such as citrus, orchids and roses. Slow release fertilizer lasts for a month or two.

Of course, proper scheduling of the application of fertilizer is very important. Fertilizer can actually become toxic with excessively frequent application. Fertilizer that provides significant nitrogen to promote vegetative growth after bloom can inhibit floral growth prior to bloom. Fertilizer that promotes root growth for new plants is unnecessary for mature plants. The diets of plants are variable.

Summer lingers later here. Regardless of the weather, it is now autumn. This is when deciduous plants start the process of defoliation for their winter dormancy. Evergreen plants are less obvious about their winter dormancy. Some remain active and even bloom through autumn and winter locally. Nonetheless, cooling weather and shortening days inhibit vascular activity of almost all plants.

Except for cool season vegetables and bedding plants, not many plants benefit from fertilizer applied this late. New plants might appreciate a bit just to help them adjust to their new environment. Some deciduous plants, particularly roses, like a last late application of fertilizer as they get ready for their long winter dormancy. Lawns might want fertilizer this late or perhaps later to stay green.

Otherwise, it is getting late to utilize fertilizer.

Late application of fertilizer can be very detrimental to plants that are sensitive to cool weather. Such plants typically finish growing through summer. By autumn, their mature foliage and stems are either resilient to minor frost, or are dieing back (defoliating) for winter dormancy. Fertilizer can stimulate premature development of new growth that will be much more sensitive to even mild frost.

Daylight Saving Time

Apologies for the lapse of posting articles as typically scheduled at midnight here for this morning and yesterday morning. The article that had been scheduled for yesterday morning posted an hour earlier, at 11:00 p.m. on Sunday night. The article that had been scheduled for this morning posted an hour earlier, at 11:00 p.m. last night. I neglected to adjust the schedule on Sunday for Daylight Saving Time.

HAPPY NEW YEAR!!!

P00101-1January 1, 2020! The first day of the Twenties!

The flora in our gardens north of the Tropics must think we are crazy for making such a fuss about it while they are trying to sleep. Even flora south of the tropics does not understand. All flora everywhere is more concerned with how the seasons change according to the position of the Earth around the Sun. Precise dates, times and numbers are meaningless.

It sort of seems odd to me that within each time zone, it is the same time and date both north and south of the Equator, but the seasons of each side are opposite. Today started in sparsely populated regions of the Pacific Ocean, worked its way through Australia earlier, and is somehow still the same ‘today’ that is here now. Yet it is winter here, and summer to the south.

Now, if January can be in the cool time of year here, and the warm time of year in Australia, it seems to me that winter could be both the cool season here, and the warm season in Australia. If the dates are the same, it seems like the seasons should be too. Alternatively, if the seasons are half a year early or late in opposite Hemispheres, it seems like dates should be too.

According to such logic, it could be either winter or July 1 in Australia and elsewhere south of the Equator right now! . . . But would that be July 1 of 2019 or 2021? Too many technicalities!

Well, it is more than the flora in the garden is concerned about anyway. It is winter here now, and summer south of the Equator. It is the beginning of January everywhere that the Gregorian calendar is used, north and south.

HAPPY NEW YEAR!

Note: ‘Horridculture’ will resume next Wednesday. It did not seem appropriate for the first day of 2020.P00101-2

Seasonal Potted Plants For Christmas

91218thumb‘Tis the season for seasonal potted plants. These are not well established houseplant or potted plants that live out on porches and patios through the year. Seasonal potted plants are those that are purchased at their prime, allowed to live in our homes and offices while they continue to bloom or maintain their foliage, and then most likely get discarded when no longer visually appealing.

Poinsettia epitomizes winter seasonal potted plants. Florists’ cyclamen, azalea, holly, amaryllis, Christmas cactus and small living Christmas trees are other overly popular choices. All are grown in very synthetic environments designed to force optimal performance, with no regard to survival afterward. They are like cut flowers that are not yet dead. They are true aberrations of horticulture.

Technically, any of them can survive as potted plants, or out in the garden after they serve their purpose as appealing seasonal potted plants. Their main difficulty is that it is not so easy for them to recover from their prior cultivation, and adapt to more realistic environmental conditions. For now, it is best to enjoy them at their best, and try to maintain them at their best for as long as possible.

Eventually, they all experience a phase in which their original growth deteriorates to some extent, while they start to generate new growth that is adapted to the situation that they are in at the time. Christmas cactus are probably the most proficient at adapting, and becoming delightful houseplants. They are even likely to bloom occasionally, although not on any particular schedule for winter.

Holly, azalea and cyclamen can eventually get planted out in the garden. Most hollies grow into large evergreen shrubbery, but do not produce as many berries as they originally did. Azaleas are cultivars that were developed to be seasonal potted plants, so are a bit more finicky than those developed more for landscapes. Cyclamen can be added to pots of mixed annuals and perennials.

Living Christmas trees are not so easy to accommodate. Most are pines that need their space.

Not Quite Rain

P91116KMost of us here agree that the minimal bit of precipitation that fell from the sky on Thursday was not real rain. There are a few different theories about what it actually was though. It could be considered to have been drizzle. It alternatively could have been heavy fog or mist. Some of us make up silly names for what it was, such as fine rain, dusting, spritzes, sprinkles or mizzle.

Is it just me, or do those last three sound like inane kitten names? ‘Dusting’, sounds dirty and dry, which it was not.

Whatever it was, it was the second occurrence of such precipitation since the rainy season ended last spring. Something similar happened on the last day of September. I wrote about it in my other blog, with a picture of it on the hood of a parked car, rather than the windshield. I think it was more of a surprise then because it was earlier, and the chance of precipitation was slim.

This weather pattern is still within what would be considered normal here. The rainy season typically starts a bit earlier, even if with just a single primary storm passing through, followed by a long pause before more follow. There is no strict schedule though. We know that the rain will eventually start, and that rainy seasons that start late tend to provide significantly more rain.

Rain is likely just as uncomfortable here as it is everywhere else. Perhaps it is even dirtier, because it rinses off dust and crud that has been accumulating since spring. No one wants to work in their garden while it is wet. Nonetheless, because there is no rain for nearly half the year, the first storm of a season is something to be celebrated. The forecast predicts no celebration yet.

Six on Saturday: The Endless Summer

 

Summer really did end here. There was a minimal frostless frost to prove it more than two weeks ago. This climate just happens to lack the more apparent seasonal changes that others get to show off. Except for a bit of drizzle last Thursday, and a bit at the end of September, there has been no rain since last spring. It may seem to be boring, but such weather is normal here.

1. There is typically more foliar color by now. Sweetgums are only beginning to yellow. However, these dogwoods started to defoliate early without much color. This is about as good as it got.P91116

2. Not all of the warm season annuals have been replaced with cool season annuals. These petunias are blooming too happily to be replaced with pansies or violas like we installed elsewhere.P91116+

3. Roses continue to bloom. This one looks like ‘Double Delight’ to me. I really do not know what it is. The flowers are rather small, so it must have noticed that nights are longer and cooler.P91116++

4. These two look silly to me because both are grafted together onto the same standard (tree rose). I believe they are ‘Iceberg’ and ‘Burgundy Iceberg’. I would not mind them individually.P91116+++

5. Even by our local standards, roses should be finishing by now, with only a few that are still blooming when they get pruned in winter. I do not know what this one is, but it still looks great.P91116++++

6. This is my favorite of these six pictures. I do not know what this rose is either. It is in a neighbor’s garden. It did not start to bloom until part was through summer, and is now at its best.P91116+++++

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

https://thepropagatorblog.wordpress.com/2017/09/18/six-on-saturday-a-participant-guide/