Junipers Should Get More Consideration

Old junipers still work like new.

Too much of a good thing eventually gets old. That is how so many of the good junipers that were so popular half a century ago became so unpopular. They became too common, and many were planted into situations that they were not appropriate for. As they matured, many became overgrown or disfigured. Only recently have a few newly introduced modern cultivars restored the appeal of both new and traditional junipers to a generation that is less familiar with their former stigma.

Even though all junipers are evergreen and somewhat similar in regard to foliar texture and their lack of interesting bloom, they demonstrate considerable diversity. Some are low and sprawling ground covers. Others are dense low shrubbery. A few develop as small trees. Branch structure may be densely compact, gracefully arching, rigidly upright, or sculpturally irregular.

Some junipers have yellowish new growth that eventually turns to a more typical deep green. Others are bluish gray throughout. A few rare types are variegated. Almost all junipers have scale-like leaves (like those of cypress). A few have needle-like leaves.

‘Blue Arrow’ and more traditional ‘Skyrocket’ junipers are like short and plump Italian cypress with bluish or gray foliage. ‘Wichita Blue’ juniper is even shorter and plumper, with more sculptural branch structure. However, it is not nearly as irregular and sculptural as the old fashioned ‘Hollywood’ juniper. Modern ‘Gold Star’ and the older ‘Old Gold’ junipers are shrubby types that exhibit arching stems with gold tips.

‘Icee Blue’ is like an improved version of the classic ‘Blue Rug’ juniper, that matures as a shallow bluish ground cover. ‘Blueberry Delight’ juniper is one of the few junipers known for conspicuous fruit, with pretty powdery blue berries against grayish needle-like foliage on trailing stems. ‘Limeglow’ juniper gets a bit deeper, and exhibits chartreuse new growth that turns rich green.

Just because junipers can be shorn certainly does not mean that they should be! Shearing deprives junipers of their naturally appealing texture and form. Instead, junipers should be selectively pruned only where necessary to eliminate growth that is beginning to become obtrusive. Stems should be cut back deeply into the main stems from which they originate, in order to avoid leaving stubs or disfigured stems. Tree junipers like ‘Hollywood’ juniper, as well as overgrown shrubby junipers, can be pruned to expose bare trunks and stems. The gnarly stems and shredding bark can be as appealing as the foliage that obscures them.

Otherwise, once established, junipers do not need much attention or water, and are remarkably resilient. They only rarely get infested with spider mites or scale insects, or get damaged by disease. They only want good sun exposure.

Last Frost Dates Help Scheduling

Frost is unlikely until next autumn.

Frost is not as much of a concern here as it is in other climates. It is very rare in some of the coastal climates of Southern California. The potential for frost damage increases farther inland, farther north, and at higher elevations. Regardless, it is generally tolerable locally. Even if it is necessary to protect a few marginal plants prior to frost, the ‘average last frost date’ gets little consideration.

The average last frost date designates the end of the frost season for a particular region. Although a specific date, it is an average of dates of the last frost of previous years. It includes minor frost that caused no major damage. Damaging frost, although possible, is unlikely afterward. It becomes more unlikely as the season advances. The process reverses after the average first frost date.

Obviously, average last frost dates are as variable as climates. They are irrelevant for climates without frost. Climates with cooler winters generally have average last frost dates later than those of milder climates. For most of us on the West Coast of California, the average last frost date happens before we are aware of it. Nonetheless, it is helpful to know the date for our particular regions.

Warm season vegetable and bedding plants should be safe in the garden after the average last frost date. Directly sown seed should get all the warmth it needs to germinate. Young plants will not likely experience damaging frost. The weather will continue to get warmer. The days will continue to get longer. Cool season vegetable and bedding plants will relinquish their space as necessary.

Plants that sustained damage from earlier frost can now be pruned and groomed. Damaged foliage that remained in place to insulate inner stems is no longer necessary. Pruning and removal of ruined vegetation stimulates new growth while it will be safe from frost. Aggressively pruning and grooming damaged plants that are already regenerating fragile new growth may be complicated.

Most local climates are beyond their respective average last frost dates. Soon, the others will be too.

Flowering Fruit Trees Without Fruit

Flowers are sometimes better than fruit.

All of the popular fruit trees produce flowers. Otherwise, they could not produce fruit. The stone fruits, such as almond, apricot, cherry, peach, plum and prune, bloom very impressively this time of year. (Stone fruits have single large seeds known as stones. Almonds are the large stones of small fruits that resemble peaches.) The pomme fruits, such as apple and pear, bloom about as prolifically shortly afterward, followed lastly by related but rare quince.

The difference between these trees and their counterparts known as ‘flowering’ trees is not so much the flowers, but the fruit. ‘Flowering’ is something of a euphemism for trees that might otherwise be known as ‘fruitless’, since they produce either uselessly small fruit, or no fruit at all.

This may seem silly to those who enjoy growing fresh fruit in the garden. However, fruit trees require so much pruning in winter, and can be so messy if the fruit does not get completely harvested. The flowering trees are happy to provide the profuse bloom without so much maintenance and potential mess. Because they were developed as ornamental trees, their flowers are more impressive, with many more shades of pink, as well as white. Many types bloom with big and fluffy double flowers.

Flowering cherry and plum are probably the most popular of the flowering stone fruit trees. Most flowering plums have purplish foliage, so are more commonly known as purple-leaf plum. Flowering almond, apricot, prune and peach are relatively somewhat rare. Most flowering stone fruit trees are completely fruitless, but some purple-leaf plum can produce messy and sour plums as they mature.

Flowering pear is probably not recognized as such because it is more often known as fruitless pear. Ironically, it can produce enough tiny pear fruit to be messier than other flowering fruit trees. Flowering pear blooms only white, and is not as florific as the other flowering trees, but grows large enough to be a mid-sized shade tree, and has the advantage of remarkable foliar color in autumn. Evergreen pear is an entirely different sort of tree that only blooms well if the weather is just so, and lacks fall color (because it is semi-evergreen).

Flowering apples are known as flowering crabapples. Unlike the other flowering trees, many flowering crabapples develop a sloppy branch structure if not pruned almost like trees that produce fruit. Yet, the weirdest of the flowering trees is the flowering quince, which is not even the same genus as fruiting quince. It develops into a thicket that blooms before everything else. Fruiting quince instead matures into a rampant tree, and blooms after the other fruit trees.

Invasive Weeds Waste No Time

Aggressively invasive exotic species become weeds.

With few exceptions, the most aggressively invasive weeds here are exotic. In other words, they are not native. They came from other regions where they were likely compliant participants of their respective ecosystems. At home, where they must compete with other members of their ecosystem, they may not be so aggressively invasive. Ecology is the opposite of a home field advantage.

Exotic species become invasive weeds in foreign ecosystems for a variety of reasons. For some, the climate is more favorable. Some grow and proliferate more freely without diseases, insects and animals that troubled them back home. There are also several that simply compete more aggressively for space and resources than native species are accustomed to. It is a jungle out there.

Most invasive exotic species are annuals. Many are biennials or perennials. Some are vines, shrubs or even trees. Most were imported intentionally, for a variety of reasons, and then naturalized. Forage and cover crops were some of the earliest of exotic species to become invasive. Other invasive species escaped from home gardens. Blue gum eucalyptus was imported for wood pulp.

Regardless of their origins or physiological forms, invasive species are weeds. They compete for the same resources that desirable plants use. They impede on the aesthetic appeal of gardens and landscapes. Some types of weeds become hazardously combustible. Even if not directly problematic, invasive weeds disperse seed that can be problematic nearby. Many disperse stolons.

Most weeds start early and grow fast to get ahead of their competition. They are more active at this time of year than at any other time. They are also vulnerable. While the soil remains damp from winter rain, they are relatively easy to pull intact. They have not yet dispersed seed for their subsequent generation. Later, they are likely to leave behind seed and bits of roots that can regenerate.

It is important to pull or grub out seedlings of unwanted shrubbery and trees, as annual weeds. They are likely to regenerate if merely cut.

Start Young Trees Off Right

Recovery is difficult for abused trees.

Young trees are so impressionable. Too much water can damage their roots, or cause them to disperse too shallowly. Improper pruning can disfigure their branch structure, and ultimately compromise structural integrity. Improper staking to keep them stable can actually interfere with development of stabilizing roots, and interfere with trunk development.

Newly planted trees will of course want to be watered from spring to autumn for at least the first year, and more likely for a few years. Those that will eventually be less reliant on watering as they mature are actually the most demanding while young, because their confined roots are not yet adequately dispersed for self sufficiency. The problem is that too much water can keep lower soil too saturated for new roots to disperse into. This causes roots to instead disperse closer to the surface of the soil, which is not only unhealthy for the trees, but puts the roots closer to pavement, other plants and any other features that they can eventually damage as they grow.

Many young trees should be pruned as they grow to eliminate structural problems, and to instead promote good branch structure. The problem is that improper pruning can actually cause structural problems that will be with the victimized trees for the rest of their lives. Pruning should leave no stubs that will take longer to compartmentalize (heal), or that might produce vigorous but weakly attached new stems.

Stakes are unfortunately necessary to stabilize new trees. The problem is that the trees can become so reliant on stakes for support that they do not develop enough trunk strength to support their canopy without stakes. That is why trees should be tied loosely enough to their stakes to be able to move at least a little in a breeze. Nursery stakes (that trees are bound to for a straight trunk in the nursery) should be removed when sturdier stakes are added.

New trees are naturally a bit more distressed than mature trees that have settled into their environment. They are consequently more susceptible to disease and insect infestation.

Spring Pruning Of Flowering Trees

Some plants prefer pruning after bloom.

Most major pruning happens while the plants that need it are dormant through winter. That is why it is known as ‘dormant pruning’. Such pruning would be so much more disruptive while plants are blooming, fruiting, foliating or growing. Pruning that happens during other seasons is not as aggressive as dormant pruning. Spring pruning, although practical for some plants, is relatively docile.

For deciduous fruit trees, dormant pruning is very important. It concentrates resources into fruit production, but also limits production to sustainable quantities. Otherwise, such fruit trees would be unable to support the weight of their own copious fruit. Spring pruning of such trees is simply too late. By that time, superfluous fruit has already consumed significant resources, only to be wasted.

Stone fruit trees and pome fruit trees are familiar examples of deciduous fruit trees that rely on dormant pruning. Stone fruits include peach, nectarine, apricot, plum and their relatives. Pome fruits are primarily apple and pear. Ironically though, their fruitless but flowering counterparts perform best with spring pruning instead. As similar as they all are, they have completely different priorities.

Flowering cherry trees bloom more spectacularly than fruiting cherry trees, but produce no fruit. Similarly, flowering crabapple trees bloom more colorfully than fruiting apple trees, but produce only tiny fruit. Neither must sustain production of significant fruit. Nor must they support the increasing weight of developing fruit. Prolific bloom is their primary function. Spring pruning accommodates.

Spring pruning allows flowering trees to first bloom as profusely as possible. Pruned out stems have already served their purpose. Because fruit production is not a concern, spring pruning is less severe than dormant pruning. Nonetheless, because dormant pruning is so practical for so many plants, spring pruning may seem impractical. It is tempting to prune dormant flowering trees now. Doing so harmlessly compromises bloom.

Blossoms Bloom Sooner If Forced

Stems of tiny blossoms really impress.

Pussywillow is an odd cut flower. It is neither fragrant nor very colorful. It just gets cut and brought into the home because the distinctively fuzzy catkins are so interesting. They are appealing alone or mixed with other late winter flowers. The otherwise bares stems can get cut just as soon as the fuzz is beginning to become visible within the swelling buds. Bloom accelerates once the cut stems are brought into a warm home.

There are actually several other plants that can provide bare twigs that can be ‘forced’ into bloom in the home. ‘Forcing’ is simply the acceleration of bloom of such twigs by cutting them and bringing them from cool winter weather into warm interior ‘weather’. Flowering quince, flowering cherry and flowering (purple leaf) plum have likely finished bloom; but forsythia, hawthorn, flowering crabapple and many of the various fruit trees that have colorful bloom will be ready to be forced any time. Some daring people even force redbud, dogwood, witch hazel, lilac and star and saucer magnolias.

When the deciduous fruit trees that bloom well need to be pruned in winter, some people intentionally leave a few spare branches to be cut and forced later, just before bloom. These include almond, cherry, apricot, plum, prune, nectarine, peach, pear, apple and a few others. When stems get cut for forcing, they should be pruned out from the trees according to proper dormant pruning techniques, and can be trimmed up accordingly when brought into the home. Flowering (non-fruiting) trees should likewise be treated with respect when stems for forcing get pruned out.

Twigs to be forced should be cut just as the flowers are about to bloom, and preferably, as a few flowers are already blooming. They should be put in water immediately, and if possible, cut again with the cut ends submerged. Buds that will be submerged when the stems are fitted into a vase should be removed.

Once in a warm home, the rate of bloom will be accelerated, although everything blooms at a particular rate. Apple and pear bloom later than most, and can bloom slow enough to justify cutting stems while already blooming. As forced stems bloom, they can be quite messy, but the mess is probably worth it.

Coppicing And Pollarding Annoy Arborists

Pollarding is a long term commitment.

Coppicing and pollarding are the most extreme of pruning techniques. They may also be among the oldest in some cultures. Yet, arborists are correct to condemn both as improper. Coppicing is the complete removal of all stems and trunks back to a stump. Pollarding is the removal of all stems back to main stems and trunks. Both procedures happen in winter, annually or every few years.

Both coppicing and pollarding stimulate vigorous and prolific cane growth during the next season. Lush foliage of such growth is useful as fodder. Foliage of pollarded mulberry is the primary food of silk worms. Canes are good kindling for the following winter. Thin canes of various species are useful for basketry. New foliage of pollarded eucalypti is useful for both essential oils and floristry.

Of course, few rely on modern urban gardens for fodder, kindling, eucalyptus oil, or basketry material.

Arborists disapprove of coppicing and pollarding because both techniques ruin trees. Many of such trees are too structurally compromised to support the weight of secondary growth after the first year. Consequently, they rely on annual coppicing or pollarding. Some trees will support their weight for a few years. Strangely though, many properly coppiced or pollarded trees live for centuries.

Coppiced trees generate from stumps of cut down trees. Ideally, they begin young. Grafted trees are less cooperative. They are likely to generate suckers below their graft unions. Pollarded trees get to develop their main trunks and limbs prior to their first pollarding procedure. The locations of the first pollarding cuts is very important. Subsequent pruning will be back to the same locations.

Distended ‘knuckles’ develop after repeated coppicing or pollarding back to the original pruning sites. Pruning must be flush to these knuckles. Stubs interfere with healing. Annual pruning leaves smaller wounds than less frequent pruning. Secondary growth should be able to overgrow wounds efficiently. Cutting below knuckles leaves wounds that may be too big to heal before they decay.

Some Shrubs Are Better Trees

Sculptural trunks are worth showing off.

So many really nifty small trees never get an opportunity to perform to their best potential. Many function so well as shrubbery that there is no need to prune them into tree form. Many just get shorn down because that is the most obvious option.

There certainly is no problem with maintaining large shrubbery as shrubbery if that is the intended function. Oleander, photinia, privet, bottlebrush and various pittosporums are all excellent shrubbery, and except for oleander, can be shorn into hedges. Yet, any of them can alternatively be grown into small trees.

‘Standards’ are shrubs that are trained onto single staked trunks. Small shrubs trained as standards, such as boxwood, azalea and euryops, are really only shrubbery on a stick. The larger shrubs though, are more often trained onto trunks about six feet tall so that they can develop as small trees with single trunks.

However, they do not necessarily need single straight trunks. Many have naturally sculptural trunks that are worthy of display. They can be planted as shrubbery, and simply trained up on a few of the trunks that they are naturally equipped with. They only need lower growth pruned away as they mature, instead of getting pruned down.

Overgrown shrubbery that has become so obtrusive that it might otherwise need to be removed can often be salvaged by getting pruned up as small trees. For example, if a New Zealand tea tree or myoporum has gotten so wide at the base that it is awkward to work around, the basal growth can be pruned away so that only upper grown that has adequate clearance remains suspended on exposed trunks. The gnarly trunks within are often more appealing than the abused foliage that obscured them.

Japanese maple, crape myrtle, water gum (Tristania laurina) and various podocarpus really are small trees, but often get shorn instead of pruned properly by ‘mow, blow and go’ gardeners who do not know any better. Olive, coast live oak and saucer magnolia are substantial trees that often get shorn into shrubbery before they can grow beyond the reach of abusive gardeners.

Hollywood juniper as well as some of the other larger junipers naturally develop into sculptural small trees that are just as appealing with or without their lower growth. The gnarly foliated stems are just as sculptural as the trunks and stems within. If space allows, they can be left to grow somewhat wildly with only occasional pruning of superfluous stems.

Summer Bulbs After Spring Bulbs

Summer bulbs start late in winter.

It was easy to bury spring bulbs so discourteously in shallow graves last autumn. None of them got proper funerals. Perhaps cool season annuals obscured their interment sites. No one needed to know they were there. It seemed like a perfect crime, until now. They are back like the undead. After all, they were not dead when interred. They were merely dormant, and likely plump and healthy.

Crocus, snowdrop, narcissus and some of the other related daffodil might already be blooming. Otherwise, their foliage is emerging above the soil. They do not necessarily wait for the soil to get warmer later in winter. Hyacinth and tulip will bloom a bit later. Delayed planting delays bloom, but only for the first season. Established spring bulbs from previous seasons will bloom as they like.

Spring bulbs, including corms, rhizomes, tubers and tuberous roots, prefer early interment for a reason. They appreciate a good chill through winter. Although most get refrigerated artificially prior to sale, they certainly do not mind a bit more chill. Besides, they also appreciate early root dispersion, even while still dormant. They prefer to bloom early, but unfortunately, also finish bloom early.

Summer bulbs are very different. They go into the garden later because they do not require chill. Furthermore, many types are sensitive to minor frost if they begin to grow too early in winter. Since they start growth later than spring bulbs, summer bulbs generally bloom later. However, some bloom for extensive seasons. A few summer bulbs bloom from early summer until frost in late autumn.

Dahlia, canna and old fashioned white calla are the more reliable of summer bulbs to plant now. Old fashioned white calla may be rare in nurseries. Smaller, more colorful, but less vigorous callas are more popular. Such summer bulbs are more sustainable than spring bulbs, and can perform for many years. Gladiolus and various lily are spectacular summer bulbs, but bloom once annually.

Incidentally, unlike the spring bulbs, most summer bulbs are actually corms, rhizomes, tubers or tuberous roots.