Exceptions To The Pruning Rules

80228thumbWinter is the best time for major pruning of most plants. They do not mind it so much while they are dormant. However, there are exceptions. Winter pruning might be a bit too early for a few plants that are grown for their late winter or early spring bloom. It is best to wait until immediately after bloom to prune or trim flowering cherry, flowering plum, flowering crabapple and flowering quince.

Because these trees will be in the process of coming out of dormancy, it is best to prune them just after the blossoms finish, as new foliage is emerging. Some of the new buds will likely be ruined in the process, but there should be plenty to spare. If a few extra stems were left on deciduous fruit trees when they were pruned earlier, they can be taken as cut flowers prior to or while blooming.

Forsythia and Oregon grape should also be pruned after bloom, but with different technique. Oregon grape certainly does not need to be pruned annually, and may only need to be occasionally groomed of deteriorating stems. If and when it gets pruned, the oldest canes should be cut to the ground to favor newer canes. Forsythia canes should be cut to the ground after their second year.

Red twig dogwood and small willows that are grown for the color of their twigs must be pruned aggressively to produce new twigs for next winter; but there is no point in pruning their colorful twigs off while they are at their best. It is better to wait until just before new foliage is about to come out and obscure the twigs. They can be pollarded or coppiced. This applies to pussy willows as well.

Clumping grasses will start to grow soon, so can be shorn of their old foliage from last year that likely started to look rather tired by the end of winter. If left unshorn, new foliage and flower stalks will do just fine, but will come up through the old growth from last year, as the old growth lays down next to it and continue to decay. Once new growth develops, it will be more difficult to remove the old without damaging the new. Clumped grasses will look silly longer if shorn too early.

Perennials Can Divide And Conquer

10810Along with all the bare root fruit trees, roses and cane berries, nurseries also stock bare root perennials like strawberries, asparagus, horseradish and rhubarb. They are so easy to plant while dormant. They recover from transplant through spring, and by summer, should be growing as if they had always been there. Although, if they had always been there, they might be crowded by now.

Yes, many but not all perennials eventually get crowded. Strawberries spread by runners, so are easily plucked and transplanted to avoid overcrowding, as well as to propagate more productive plants. Asparagus are variable, so may not get crowded for decades. Horseradish and rhubarb may not mind getting crowded, but could be more productive if individual plants have their space.

For example, crowded horseradish plants produce many small roots. If dug, split apart, and replanted with more space between individual plants, the individual roots get much larger. Separating the roots, which is known as ‘division’, also produces many more new plants. Mature rhubarb plants may not mind being crowded, but are often divided simply to propagate new productive plants.

Division of these sorts of perennials is typically done while they are dormant through winter. If that sounds familiar, it because it is the same reason why these sorts of perennials are available as bare root stock. They get processed while they are unaware of what is happening, and wake up in their new and better situations. Many defoliate while dormant. However, most are evergreen.

Ornamental perennials like lily-of-the-Nile, African iris, New Zealand flax, society garlic, torch lily, lily turf and acorus grass are all good candidates for division if and when they become overgrown. So are most aloes, some terrestrial yuccas, several ferns and some of the more resilient clumping grasses. Agave pups can be dangerous, but really should not be allowed to get too crowded.

Division might be as simple as taking a few pups or sideshoots from a large clumping plant, or as involved as digging an entire large plant to divide each individual shoot. More often, large plants get dug and split into a few smaller clumps of many shoots. New plants should be groomed of deteriorating foliage. The long leaves of New Zealand flax should be cut in half to avoid desiccation.

Pollarding And Coppicing Pruning Techniques

80221thumbJust about any other arborist will say that pollarding and coppicing are wrong. These techniques ruin trees so that they can never develop into their natural form. Although restorative pruning after pollarding or coppicing is possible, it is usually more trouble than it is worth. However, no one can deny that properly pollarded and coppiced trees can live much longer than they would naturally.

Pollarding and coppicing are extreme pruning. Coppicing is literally cutting a tree down to a stump just above the ground. Pollarding is almost as severe, but allows the main trunk and main limbs to remain. It does not end there of course. It must be repeated annually to maintain the coppiced stump or pollarded trunk and limbs. Secondary growth gets pruned off, back to the previous cuts.

After this process is repeated for a few years, coppiced stumps and pollarded limbs develop distended ‘knuckles’. Cutting back to but not below these knuckles facilitates compartmentalization (healing) of pruning wounds. Because the secondary growth is only a year old when cut annually, the wounds are relatively small, so they get grown over by new growth during the following season.

English style pollarding leaves one or two stubs of any desired length on each knuckle annually. These stubs are generally but not necessarily selected from stems that are aimed upward and outward. This technique elongates knuckles so that the trees are more gnarly and sculptural. Otherwise, all other stems must be pruned away cleanly. Stubs interfere with compartmentalization.

Pollarding and coppicing are done while trees are dormant in winter, and only to the few specie of trees that are conducive to it. These techniques were historically used to generate firewood, wiry willow stems for weaving baskets, straight fence stakes, or lush foliage for livestock and silkworms. Nowadays, they are done to keep big trees small, enhance the size and color of leaves, enhance the color of bark (on twiggy secondary growth), maintain juvenile foliage, or to prevent the bloom of allergenic flowers.

Roses Get Pruned In Winter

30508thumb++Winter is no excuse to be less diligent in the garden. It would seem that gardening would be less demanding because there is less going on, and so many plants are dormant. However, dormancy is precisely why there is so much to do through winter. Bare root plants and bulbs are planted because they are dormant. Fruit trees get pruned because they are dormant. Now it is time for roses.

Just like fruit trees, modern roses were intensively bred for enhanced production. Their flowers are too big and abundant for overgrown plants to sustain. Consequently, aggressive specialized pruning is necessary to concentrate resources and promote vigorous growth. Rather than producing an abundance of inferior blooms, well pruned canes produce fewer blooms of superior quality.

Also like deciduous fruit trees, roses should be pruned while dormant, preferably after defoliated, and before new buds swell. This sounds easier than it really is. Some roses might still be trying to bloom on canes from last year. Others might be trying to generate new foliage for this year. Fortunately, they are tougher than they look. Besides, early or late pruning is better than no pruning.

Hybrid tea, floribunda and grandiflora roses need the same sort of pruning. They all should be pruned back to only a few canes that grew last year. Older canes should be pruned out completely, unless there are not enough new canes that grew last year. Hybrid tea and floribunda roses need only three to six canes, only about two feet tall. Floribunda roses might have a few more canes. Tree roses should be pruned just like shrub roses, as if the upper graft union is at ground level. The canes can be pruned shorter.

Suckers from below the swollen graft union (from where canes emerge) should be removed completely. If possible, they should be pulled or peeled off instead of cut. This seems harsh, but leaves less of a stub from which more suckers might develop later. Because fungal spores and bacterial diseases overwinter in decomposing foliage, fallen leaves should be raked from around roses.IMG_20140331_112633

Bulbs Are Not Finished Yet

41015thumbIt might seem creepy to think about what spring bulbs are doing right now out in the garden. Like victims of a horror movie, they were buried in shallow graves last autumn. They were not dead though. They were undead but merely dormant. While no one can see what they are up to, they disperse roots and begin to push new foliage up to the surface of the soil. Some might bloom soon.

Now it is getting to be time for summer bulbs. Unlike spring bulbs, summer bulbs do not prefer to hang out in the garden through the cool and rainy weather of winter. If planted too early, they can start to grow prematurely, and could potentially get damaged by frost. If planted much too late after winter rain, they will need to be watered more carefully while young, and are likely to bloom late.

Just like spring bulbs, most summer bulbs are really corms, rhizomes, tubers or tuberous roots. Only a few are actual bulbs. Although they are very different physiologically, they perform the same function. They store resources from a previous season through dormancy in order to sustain growth for the next season. Some summer bulbs bloom more than once annually or with many blooms.

Dahlia, canna, crocosmia, hardy orchid (Bletilla) and the old fashioned big white calla are some of the easier to grow summer bulbs. Dahlia is the most colorful, but blooms late in summer or early autumn, and might only perform well for a single summer. With regular watering, canna can grow like a big weed, but in a nice way. The others can grow well enough to get invasive over the years.

Gladiolus and lily will probably bloom for only one summer, but are so colorful that those who enjoy them do not mind. Tuberous begonia is fussier, so is usually grown in pots. Allium, astilbe and maybe liatris have potential to thrive and multiply in the right conditions, but more often bloom for only a few years. Small colored callas are unpredictable too. They are showy but rarely prolific.

After bloom, deteriorating flowers should be pruned away to conserve resources while lingering foliage recharges bulbs for the next winter. This process is known as ‘deadheading’. Gladiolus, lily and any others bulbs that bloom only once obviously need to be deadheaded only once. Dahlia, canna and others that bloom over an extended season will want to be deadheaded a few times.

Colorful Berries Feed Overwintering Birds

80214thumbPlants compensate for their immobility by procuring the services of animals and insects. They bloom with flowers that attract pollinators with colors, fragrances and flavors. Their fruits use similar techniques to attract those who consume the fruits to disperse the seeds within. It is a pretty ingenious system. The animals and insects probably think that they are taking advantage of the plants.

Firethorn, toyon, cotoneaster, English hawthorn and the hollies all produce profusions of small bright red berries that are designed literally for the birds. They are just the right size for birds to eat them whole. If they were smaller, birds might prefer other fruits. If they were any bigger, birds might eat them in pieces, and drop the seeds. The bright red color is a blatant advertisement to birds.

Firethorn is probably the most prolific with its berries. It might also be the most popular with the birds. If the colorful berries are not gone yet, they will be soon. Toyon berries seem to last longer, perhaps because they do not all ripen at the same rate. Because it gets big and takes some work to contain. toyon is more common in unrefined landscapes and in the wild than home gardens.

English hawthorn and cotoneaster are variable. Some varieties are more productive with berries than other are. Some types of English hawthorn are grown more for their bloom or foliar color in autumn. They are deciduous, so their berries hangs on bare stems. Late cotoneaster produces more berries than other cotoneasters, and somehow manages to keep its berries late into winter.

Holly is not related to firethorn, toyon, cotoneaster or English hawthorn, which are all in the Rosaceae family, although the bright red berries suggest that it should be. Because most holly plants are females that lack a nearby male pollinator, berries can be scarce. Some plants in nurseries are actually two plants together in the same pot, one male and one female, to ensure adequate pollination and berry production. Deciduous hollies are unfortunately rare.

Herbs Add Spice To Life

80207thumbOut in deserts, where vegetation can be a scarce commodity, cacti, agaves and yuccas protect themselves from grazing animals with thorns, spines, caustic sap and distastefully textured foliage. None of these defense mechanisms is perfect. They only need to be better than what the competing specie are using. Many plants find that objectionable flavor and aroma work just fine for them.

The funny thing about the objectionable flavors and aromas that some plants use to discourage grazing animals from eating them, is that these same flavors and aromas are what make so many of them appealing to people. It is ironic that what was supposed to make them distasteful to some is what makes them tasty to others. Yet, it also gets us to perpetuate them in our home gardens.

Mint, thyme, lavender, rosemary and sage, which all happen to be in the same family, are culinary herbs that also work well in the landscape. The mints need the most watering, and containment if their innate invasiveness is a concern. Thymes need less water, and some are nicely aromatic ground cover for small areas. Lavenders and rosemaries can survive with minimal watering here.

Both rosemary and sage are popular for landscaping anyway. Rosemary is most commonly grown as a ground cover that cascades nicely over low retaining walls, but some cultivars are shrubby. Sages are extremely variable. Some are showier than they are useful in the kitchen, with elegant and colorful flower spikes. Others are too strongly aromatic to cook with, but are used as incense.

Fennel and chamomile are often grown in vegetable gardens rather than out in the more refined parts of the landscape because they can get somewhat awkward. Fennel has such nice feathery foliage at first, but if not harvested, it gets tall, and then yellows after bloom. Chamomile gets tall and open in bloom, and then no one wants to ruin it by harvesting all the flowers if it looks too good. Chives are easier to work with. They have so many leaves that no one misses a few taken for the kitchen.

Rain Is Necessary But Messy

10914Water is no more scarce in California than it has been in recorded history. The problem with it is that it is a limited resource that must be shared amongst too many people. Likewise, rainstorms are no more torrential than they have ever been. Floods, erosion and wind are only more destructive now because there is so much more infrastructure that can be damaged than ever before.

Rain and wind are perfectly natural. Furthermore, it is natural for the weather to knock down limbs or entire trees. It only seems unnatural when these limbs or trees fall on houses, cars or anything else that gets in their way. Plants actually enjoy rainy weather much more than we do. Some like to be rinsed of dust and debris left from former infestations of mites, aphid, scale or sooty mold.

What plants do not like about rain is erosion. It is bad enough that so many plants in refined gardens are deprived of their own litter to insulate the surface of the soil. It is even worse if the bare soil gets eroded away from fine feeder roots at the surface of the soil. This is something that the rest of us would agree on. We do not want gullies carved into slopes, or drains clogged with mud.

Trees, shrubs and some stout perennials with aggressive roots are useful where the potential for major erosion is a concern, but might not do much for annoying surface erosion. Sprawling and spreading plants that form dense networks of low branches and surface roots are more effective. They soften the splatter of rain, slow the flow of drainage, and catch much of any dislodged silt.

Groundcover plants like ivy, gazania and iceplant are probably the best option for controlling surface erosion. Dense and low shrubbery that spreads over the ground and holds its own debris probably work just as well. These include low junipers, trailing rosemary and dwarf coyote brush. Larger shrubbery can help if it can drag its lowest limbs on the ground, and no one rakes below it.

Mulching limits erosion while new plants grow. Although new mulch needs to be added annually as old mulch decomposes, less will be necessary as plants grow and cover more area. Mulch is also effective where no plants are desired. For large areas, especially where plants are not expected to fill in, landscape cloth below ornamental bark inhibits weeds. However, coarse bark slowly shifts downhill, so replaces one kind of erosion with another, and will eventually need to be raked back uphill.

When Life Gives You Lemons

80131thumbWhen life gives you lemons, it is likely this time of year. Although, the most popular garden varieties of lemon, like ‘Meyer’ and ‘Eureka’, continue to produce at least a few more fruits sporadically through the year. ‘Lisbon’ lemon that is still used in orchard production, and is the ancestor of the household ‘Eureka’ lemon, produces almost all of its fruit in winter, and blooms shortly afterward.

Ripe citrus in the middle of winter impresses those in climates where winter is too cold for much to happen in the garden. They could not grow a citrus tree if they wanted to. Even here, frost can damage some of the more sensitive citrus varieties, like ‘Mexican’ lime. Unlike the fruits of summer, citrus fruits ripen slowly and are not so perishable, so do not need to be harvested right away.

This means that if it is raining, cold or just to wintery to go outside, citrus fruits can be left on the tree until the weather improves. Most of us prefer to pick them in small batches anyway. Ideally, fruit should get picked as it is consumed. Lemons and limes typically get picked individually as needed, until there are so many that some need to be bagged and shared with friends and neighbors.

Mandarin oranges are the most perishable of the citrus. Because their skins are so loosely attached to the pulp, the pulp can oxidize, lose flavor and eventually get dry and pithy. Incidentally, a ‘tangerine’ is merely a Mandarin orange that was developed in North or South America. A surprisingly sour (unknown) Mandarin orange might really be a ‘Rangpur lime’, which is not a lime at all.

Unlike most fruit that continues to ripen after harvest, or pears that actually delay ripening until after harvest, citrus fruits stop developing flavor once picked. It is best to taste them for confirmation of ripe flavor prior to harvest. Some Mandarin oranges may have slightly greenish blotches on them even when completely ripe. The best ‘Valencia’ oranges can look rather yellowish. Grapefruits might mellow if left in their trees past ripeness, but can also inhibit bloom.

Berries Are For The Birds

51125It is probably no coincidence that certain berries and small fruits are so colorful through winter while colorful flowers are relatively scarce. Like flowers, they want to get others to do something for them. Flowers use color, aroma, flavor and sometimes even texture to attract and reward pollinators. Colorful berries and fruits do the same to attract birds and animals who disperse their seeds.

There are not many colorful flowers blooming in winter to distract anyone from colorful berries and fruit. Those who want them are pretty intent on finding them anyway. There is not much else for overwintering birds to eat. Squirrels probably have plenty of acorns and nuts stored, but might enjoy a few berries too. No matter how abundant they are, there is serious competition for berries.

Most types of berries and small fruits that are so colorful through winter contain tiny seeds that get eaten along with the fruit. In this manner, the seeds get taken away from their origin as easily as birds fly away. They then get dispersed as birds do what birds do (that can be so annoying on a freshly washed car). Digestion only scarifies these seeds, which might not germinate otherwise.

This all might be much more information than necessary for home gardening. All we really need to know is that there are several plants that can produce colorful berries through winter while other color is limited. Although, it might be useful to be aware that these colorful berries are likely to eventually be depleted by the birds and any other wildlife that they are intended to be appealing to.

Then again, winter berries are popularly grown specifically to attract birds and wildlife to the garden. Either way, if berries are grown for their color or to attract birds, they have the potential to be messy. Those that do not get eaten eventually fall onto whatever is below them. Those that do get eaten fall (in ‘another form’) all over the neighborhood, and of course, onto freshly washed cars.

Coincidentally, most plants that produce colorful winter berries are related. They are of the ‘rose’ family, ‘Rosaceae’, and produce similar ‘pomme’ fruits that look like minute apples. Firethorn (pyracantha) is the most colorful and prolific. The various cotoneasters, including some low growing ground-covers, are similar, but not so prolific. Toyon is a colorful native that works nicely in unrefined landscapes. English hawthorn is a small deciduous tree.