Winter Annuals Are Moving In

Chrysanthemums bloom between summer and winter.

It is inevitable. It begins at about the same time that cool season vegetable plants start to replace warm season vegetable plants. Cool season vegetables are now in season, and will grow during autumn and winter. They replace warm season vegetables of spring and summer. Winter annuals, or cool season annuals, now do the same for summer annuals. 

Some summer annuals, or warm season annuals, are already shabby by the end of their season. Their replacement is not so unpleasant. Those that continue to perform well into the end of summer or autumn are a bit more difficult to evict. No one likes to pull them up while they still bloom colorfully. Besides, new winter annuals may take a while to bloom.

Winter annuals, as well as summer annuals, require replacement because they live only for a single year. Some complete their respective life cycle within only a few months of a year. That is what their designation as ‘annual’ means. Several annuals have potential to survive as perennials, but are too unappealing to salvage through their dormant season.

Marigold and chrysanthemum are popular for autumn, but do not perform as well through winter. Cyclamen, which prefers a late start, is pleased to replace them by then. Although chrysanthemum and cyclamen are both perennials, few get the opportunity to perform as such. It is easier to simply remove and replace them with the next best seasonal annual.

Pansy, viola, Iceland poppy, sweet William, stock and various primrose are all in season now and through winter. Calendula and snapdragon are seasonable for autumn, and will be again for early spring. They survive and can even bloom through the middle of winter locally. Alyssum is technically a summer annual, but might bloom all through winter also. 

Winter annuals are not as easy to grow from seed as summer annuals are. Because they grow during cooler weather, they grow slower. They therefore need to start growing early to be ready for planting now. It is perhaps more practical to plant most types as seedlings from cell packs. Cyclamen and ornamental cabbage commonly grow from four inch pots. These are innately more expensive than other winter annuals.

Cool Season Annuals Are Cool

Warm season annuals are now passé. Cool season annuls, such as these violas, are in.

Now that it is time for cool season annuals, it is difficult to remove warm season annuals if they are still blooming and healthy. that is probably why so many of us prefer mixed plantings, where cool season annuals can be added as needed to replace warm season annuals as they deteriorate. Some warm season annuals that are actually perennials, like wax begonia and busy Lizzie (impatiens), can be cut back and overplanted with cool season annuals, so that some might regenerate next spring as the cool season annuals finish. Petunias may be looking overgrown and tired, but are at least easier to remove without guilt.

Pansies and smaller but closely related violas are probably the two most popular of cool season annuals. They work something like petunias, but for autumn and winter. They are commonly grown in uniform beds, but work just as well in mixed plantings. There are not many colors that can not be found in pansies, although only a few of the more popular varieties can be found at any particular nursery. Some are ‘solid’ colors. The most familiar varieties have those funny ‘faces’ that pansies are known for.

The various primroses require a bit more effort because deteriorating flowers need to be removed. They can also be a problem for the few who are allergic to them (like poison oak). Like the warm season annuals that can survive as perennials through winter, some primroses, particularly English primrose, can survive through summer as perennials. English primrose displays bright cartoon shades of almost any color. Fairy primrose are more commonly pastel shades.

Stock has an intense and distinctively rich fragrance. Taller types are excellent cut flowers, but are not so practical for uniform beds. Even shorter types are probably best in mixed plantings, or in borders with lower flowers in front. The single or double flowers can be white, pink, purple and almost red.

Ornamental cabbage and kale are grown for bold rosettes of colorful pink, white or pink and white foliage. The shades of pink range from soft light pink to rich purplish pink and almost red bright pink. Cabbage provides more color. Kale has more variety of foliar texture. Ironically, both look rather weedy, and should be removed as they begin to bloom in spring.

Chrysanthemum are strikingly colorful cool season flowers, but rarely bloom as uniformly as they do when first planted. Because they bloom so profusely, they need to be groomed frequently. If they get what they want, they can perform for several years, blooming all sorts of shades of yellow, orange, red, pink, purple and white. Chrysanthemum also displays a broad range of flower structures and sizes, from minute to jumbo.

Sweet William, Iceland poppy, calendula and alyssum are also in season. Yellow or orange calendula, with single or double flowers, is best through autumn, but may mildew by winter. Alyssum is white or subdued shades of pink or purple, and is actually good throughout the year, and can self sow indefinitely.

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.

Gardening Has Something In Common With Automobiles.

Buick is the genus. Electra is the species. Buick Electra is universally the most elegant luxury sedan of all time!

Horticulturists, biologists, and many other professionals who may interact with colleagues who speak other languages or even slightly different regional dialects use Latin to identify, among other things, biological organisms. Latin names may be cumbersome to pronounce and daunting to spell, but are universal to those of us who use them. This is important because common names are so regionally variable.

For example, some of the European maples that we know as maples here are known as sycamores in England, but are known everywhere by their Latin name of Acer. Similarly, North American sycamores that are known as maples or plane trees in various regions are all likewise known everywhere by their Latin name of Platanus. The universality of Latin names therefore facilitates accurate identification.

Latin names are very helpful when researching plants. A tree known simply as a ‘cedar’ might be a calocedrus, arborvitae, juniper, cypress, chamaecyparis or a true cedar, just to name a few. Knowing that the particular tree is more specifically a ‘red cedar’ perhaps limits the possibilities to arborvitae or juniper. Identifying the tree specifically as a Juniperus virginiana will help us find the most accurate information about it, even though it is not really a cedar at all, but a juniper. Juniperus is the general ‘genus’ name of all junipers. Virginiana is the specific ‘species’ name of the particular juniper that is known locally as the Eastern red cedar. (‘Genera’ and ‘specie’ are plural for ‘genus’ and ‘species’.)

Latin names work like the names of cars. Buick, Chrysler and Mercury are all like genus names. Electra, Imperial and Grand Marquis are all like species names of particular Buicks, Chryslers and Mercurys. ‘Limited’, ‘Custom’ and ‘Brougham’ are like variety names, like ‘Variegata’, ‘Compacta’, and ‘Schwedleri’.

As universal as Latin names should be, a few sometimes get changed. This can be confusing, and causes some plants to become known more commonly by either their new or old name, as well as the other name as a ‘synonym’. For example, Dietes bicolor and Morea bicolor are the same plant; but not many know for certain which name is more correct. It is like when Datsun became Nissan, but was also known as Datsun for many years afterward.

Thorny Vegetation Is Naturally Repellent

Black locust is painful to handle.

Roses might be more fun to grow and prune without their thorns. Blackberries are easier to pick from thornless canes. Thorny vegetation is simply unpleasant to work with. Some very desirable plants, such as roses and most blackberries, are innately thorny. The only alternative to contending with their thorny condition is to grow something totally different.

Thorns and similar structures are as diverse as foliage, with a few distinct classifications. True thorns are simply modified stems, like those of hawthorn. Spines are modified foliar structures or leaves, such as those of cacti. Prickles, such as those of rose, are modified epidermal structures. Spinose foliar margins, like those of holly, serve the same purpose. 

The purpose that thorny vegetation serves is defense. It intends to inhibit consumption of foliage, fruit or bloom. That is why some trees are thorny only while young and low to the ground, then almost thornless as they grow beyond the reach of grazing animals. Thorny trunks of honeylocust may protect seed pods from bears, so birds can disperse the seed. 

It is therefore no mystery that many of the thorniest plants are endemic to desert regions. The scarcity of edible vegetation in such regions increases the need for protection. Also, it is no mystery that most grazing animals are not too deterred by thorny vegetation to get enough to eat. Otherwise, roses and firethorn would be exempt from the ravages of deer.

Despite its intentions of deterrence, thorny vegetation inhabits home gardens for various reasons. Some produces desirable bloom or fruit, like roses and blackberries. Cacti and agaves develop remarkably striking forms. Such plants should be situated appropriately. Rose canes can be bothersome close to walkway. Agaves can be downright dangerous. 

Thorny shrubbery, such as firethorn, barberry, Natal plum and English holly, is a practical deterrent for unwanted traffic. Firethorn espaliered on the top of a fence is as effective as barbed wire, and is more appealing. Maintenance of thorny plants is more of a challenge than for thornless plants. Otherwise, thorny plants should be more popular than they are.

Ferns Are For Distinctive Foliage

Rich green ferns provide distinctive texture.

Ferns are an odd group. They lack the color or fragrance of flowers, or the branch structure of shrubbery, trees or vines. Very few turn color in autumn. They provide only green foliage. Yet, as simple as this seems, the generally evergreen foliage that ferns provide is some of the most distinctive foliage that can be found in the garden.

With few exceptions, ferns are richly deep green. Only a few are lighter green or almost yellowish. The leaves, which are known as ‘fronds’, can be soft and papery, or coarse and tough. The fronds of most ferns are pinnately divided into neatly arranged leaflets; and many ferns have leaflets that are intricately lobed. Some ferns have leaves with more palmate symmetry. A few ferns actually have undivided leaves.

(Pinnate symmetry involves a central midrib or midvein to each leaf, or a central rachis that supports lateral leaflets. Radial symmetry involves multiple midveins or rachi that radiate outward from the centers of individual leaves.)

The Australian tree fern is the largest of the common ferns. It develops a broad canopy of long fronds on top of a trunk that can launch it as high as a two story home. Both the fronds and trunk of the Tasmanian tree fern are shorter and stouter. Other tree ferns are rare. The trunks are not really stems, but are thick accumulations of roots dispersed through decomposed stem tissue.

The staghorn fern is an epiphyte that naturally clings (nonparasitically) to trunks and limbs of trees. The flared upper fronds collect foliar litter that falls from the trees above to sustain the roots within. In home gardens, it is popularly grown on wooden plaques or hung like hanging potted plants, but without a pot.

Some ferns can be grown as houseplants like the classic Boston fern, which cascades softly from a hanging pot. Maidenhair fern is popular for intricate foliage on wiry rachi (leaf stems). Squirrel foot fern has lacy foliage and interestingly fuzzy rhizomes that creep over the edge of a pot.

Since almost all ferns are understory plants that naturally live on or near a forest floor below a higher canopy of trees, they are generally quite tolerant of shade. In fact, most prefer at least some sort of partial shade. This is quite an advantage for spots in the garden that are too shady for other plants. Also, many ferns can disperse their roots into soil that is already occupied by more substantial plants, even if the more substantial plants happen to also be making the particular spot too shady for other plants. In other words, they play well with others.

However, many ferns are more demanding than other plants are in regard to soil quality and watering. They perform best with rich and well drained soil, and regular watering. Sickly ferns generally respond well to fertilizer; but too much fertilizer can burn foliage. Old leaves may need to be groomed out if they do not naturally get overwhelmed by new foliage.

Produce Fresh From The Garden

Cucumbers grow in spring or autumn.

Plants notice it before people do. They respond accordingly. Vegetative growth slows or stops completely. Most remaining bloom does likewise. Fruit and seed finish developing. Less fresh produce is available from the garden. Boston ivy and Japanese maples might already be changing color. They all know that the days are shorter and nights are cooler.

Warm season produce gets less abundant as summer ends because most is fruit, which contain seed. Most plants naturally finish with seed production prior to autumn. Most cool season produce is truly vegetative and lacking seed. It naturally grows during autumn or winter, with the (‘fruitless’) intention of blooming and fruiting during the following season.

It seems as if warm season vegetables were replacing cool season vegetables from last winter only a few months ago. Perhaps they were. That process began about half a year ago, but never completely stops. Various phases of various vegetables start and finish at various times. Now, some warm season vegetables might continue to produce until frost. 

Corn is of those warm season vegetables that remain productive. Seed for the last phase would not have been too late if it got into the garden two weeks ago, but will take time to produce. Broccoli seed sown at the about same time could be the first of the cool season vegetables in the garden. However, it is likely more practical to plant seedlings a bit later. 

Seed for cabbage and cauliflower can go into the garden now. Alternatively, it should do as well in flats or cell packs, for later planting. This procedure delays their occupation of garden space, which might still be occupied by late warm season produce. Besides, it is easier to defend tiny seedlings in flats or cell packs from slugs, snails, birds and insects.

For big and leafy cool season produce, it may be more practical to purchase seedlings in cell packs rather seed. Since only a few seedlings of each type are needed, they are not too much more expensive than seed. However, confinement to cell packs disfigures root vegetables, such as beets and carrots. Their seed can get into the garden in two weeks to a month.

Late Summer Bloom Until Frost

Some flowers bloom at odd times.

Seasonal changes keep gardening interesting. Like colors of a rainbow, seasons are not as distinct as their dates on a calendar imply. Each evolves into the next. Spring evolves into summer. Late summer is presently evolving into autumn. It happens like red evolves into orange on a rainbow. It is amazing that plants can monitor the changes so precisely.

Even if plants could monitor calendars, they would not. They are too busy monitoring the daily duration of sunlight. That is how they identify primary seasonal changes. Of course, they monitor the weather also. That is how they know more precisely when to react to the seasonal change. Plants are aware that it is now late summer, and they know what to do.

Most but not all plants bloom during spring or summer, so finish by late summer. By now, they prefer to prioritize seed production. Some continue to produce fruit to entice animals who eat it and disperse its seed within. However, some plants prefer to bloom late. Some bloom during autumn or winter. Some are so late that they are early during the next year.

Therefore, there is more to provide floral color through late summer and into autumn than cool season annuals and late blooming perennials. Butterfly bush, plumbago, bee balm, lion’s tail, Saint John’s wort and various salvia are now blooming for late summer. Some might continue into autumn. Oleander and euryops might bloom sporadically until winter.

Strangely, some flowers that bloom for late summer or autumn are from tropical climates. Because equatorial or tropical climates are not as cool during winter, or may lack winter, shortening days are not such a deterrent to bloom. However, many tropical plants bloom sporadically, rather than profusely within a particular season, and may be unpredictable.

Princess flower, mandevilla, hibiscus and angel’s trumpet may bloom at any time prior to winter chill, but may not. Those that do so may not repeat the process annually. Fuchsias are a bit more reliable for late bloom with flowers that are generally more interesting than colorful. Blue hibiscus looks more tropical than it is, with potential for late summer bloom.

Color Wanes As Summer Ends

Summer blooms will be finishing soon.

Black-eyed Susan, sunflowers and a few of the late warm season annuals and perennials are still blooming, and a few will continue into autumn. By that time, cool season annuals can move in; and some of the deciduous trees, shrubs and vines that turn color for autumn will be doing so. Realistically though, this can be the leanest time of year for color in the garden. Even some of the foliage that is colorful through spring and summer has faded.

There are certainly plenty of flowers in season now. However, not many are colorful. Honeysuckle vine is pleasantly fragrant as it bloom in random phases until the weather gets cooler, but the flowers are only pale yellowish white. Some melaleuca trees bloom profusely enough to make a mess, but are just as pale, and do not even provide fragrance; although some have pretty light pink flowers. Abelia flowers are pink and abundant, but are really not all that flashy against their bronzy foliage.

Some of the more colorful flowers are not quite as reliable. Princess flower, hibiscus, blue hibiscus and mandevilla certainly can bloom in late summer or autumn, but sometimes bloom earlier than expected, so have nothing left for later. The bright red flowers of blood red trumpet vine are quite impressive, but only if they are not obscured by the accompanying foliage. Some roses bloom in phases as late as the weather will allow, but actually, most are done by now.

Fuchsia and angel’s trumpet likewise bloom in a few phases once they get started, but unlike the many cultivars of roses, they are much more reliable for a late bloom phase. Escallonia blooms late with small but colorful flowers, but only if they have not been shorn in the past few months. Shearing deprives them of the blooming stem tips that they had worked most of the year for.

Butterfly bush, tree mallow, cape plumbago, bee balm and several varieties of sage and salvia are among the most reliable plants for late summer or autumn bloom. Even without multiple bloom phases, they just naturally bloom at the end of their growing season, before winter dormancy.

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.