Avocado

60217Avocado trees, Persea americana, grown from seed need to be about five years old to produce fruit that can be considerably different from the fruit from which the seed was taken, although such fruit is almost always quite good. Some trees need to be twice as old to produce. Grafted trees from nurseries are specific varieties that can start to produce their specific fruit immediately.

Fruit production is notoriously variable. Some healthy trees may be unproductive for a few years, and then suddenly produce more fruit than the limbs can support. Trees that are very reliable and productive may sometimes be unproductive or significantly less productive for a season. It is nearly impossible to determine which environmental factors inhibited bloom and fruit development.

Mature trees can be more than forty feet tall, with awkward branch structure. The lush dark green leaves are about four to eight inches long. The tiny yellowish green flowers barely get noticed until they deteriorate and fall to the ground like corn meal. The dark green and pear shaped fruit is quite heavy. It develops on the tree, but then ripens after it falls or gets picked and brought inside.

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Warm Weather Confuses Dormant Plants

60217thumbClimate is what makes gardening so excellent here. It is just warm enough in summer for plants that like a bit of heat, but not too unbearably hot for too long. It is just cool enough in winter for plants that like a chill, but not cold enough for hard frost or heavy snow. The climate is also comfortable for us while out in the garden! Yet, even local climate is neither perfect nor predictable.

El Nino is still out there, and likely to deliver an abundance of rain. The rain last month was great while it lasted. This presently dry and warm weather in between has been excellent, but is likely to cause serious consequences. Some deciduous plants that are normally bare through winter are being deprived of adequate dormancy. Some are blooming prematurely, and may foliate soon.

When the rain resumes, it will ruin some of the premature bloom. This is generally harmless for most fruitless flowering trees like the various acacias, flowering plums and saucer magnolias, but compromises their most alluring feature. It can be more dangerous to flowering pears (including evergreen pear) and flowering crabapples, because wet blossoms can be infected with fire blight.

The more serious problem is that rain ruins blossoms and juvenile fruit of various deciduous fruit trees. Stone fruits such as almonds, apricots, cherries, plums, prunes, peaches and nectarines bloom first, and do so with delicate blossoms. If the blossoms do not get knocked off by rain, the juvenile fruit will rot if it stays damp too long. Many fruit trees are likely to lose all fruit this year.

Apple and pear trees should be safer because they bloom later, and bloom with more substantial flowers. (However, like their fruitless relatives, their wet blossoms are very susceptible to fire blight.) Persimmons and pomegranates bloom even later, and with even tougher flowers, so should be safe. Figs are in a league of their own, and should be fine if summer is warm.

Fortunately, destruction of bloom and fruit, although disappointing to us, is harmless to the affected trees.

Horridculture – Cruel and Unusual Punishment

P90213This landscape is nothing fancy. It is out in front of a fast food establishment on Ocean Street in Santa Cruz. It is low maintenance, and starkly simple. It would be nice if the so-called ‘gardeners’ would cut back the African iris and English lavender a bit better, but they may have left them like this so that they are less likely to get trampled. The colored chips get replenished regularly, and the trash gets harvested quite efficiently. As I said, it is nothing fancy. The only remarkable feature had been this exemplary crape myrtle in the middle.
Only a few weeks ago, it was a perfect small specimen. Even though it is still quite dinky, the main stems were all at good angles, well spaced and aimed in the right directions. None of the stems were crossing over others, damaged or otherwise misshapen.
I can not explain what happened here since then. Are the so-called ‘gardeners’ trying to make more work for themselves by causing problems that will likely need their attention in the future? Do they just hate their work as much as this abuse implies? Is it possible that someone really believes that ‘this’ is somehow beneficial to the victim?
Each of the two fence stakes is sufficient to support a small tree, if such a tree needs it. If a tree, or in this case, a multi-trunked tree, does not need support, it should not be supported. Otherwise, it becomes reliant on the support. Besides that, these are fence stakes that are designed to be somewhat permanent. Now that they are there, they will probably be there forever. So-called ‘gardeners’ who do this sort of thing are not the sort to remove stakes.
The nylon straps are not flexible to accommodate the expansion of the stems they are tied around. If not removed, they will constrict, or ‘girdle’, the growing stems. What exactly are the straps doing anyway? The two closest to the bottom are tied to one stake, and pass the other to reach the respective stems that they are tied to, rather than tied between each of the two stems and the stake that it is closest to.
Someone certainly put a lot of effort into a whole lot of uselessness that will interfere with the healthy development of this formerly exemplary crape myrtle. Yet, with all this effort, no one bothered to prune it, or even so much as deadhead it. Yes, those are deteriorated floral stems from last summer.P90213+

Blue Festuca

90220To avoid confusion with dwarf fescue blue turf grass, Festuca ovina glauca is more familiarly known as blue festuca. If planted close together and left to spread as a small scale ground cover, it is much lumpier and mounding than uniformly spreading turf. It is a clumping perennial that is more popularly grown as distinct tufts of finely textured blue gray foliage that looks like gray sea urchins.

Either individually, or in small herds, these resilient gray sea urchins mix nicely with brightly colored flowering annuals. They do not need too much water, but can tolerate as much as annuals want. Their color is best in full sun. Partially shaded plants are greener, with longer and more pliable leaves. So are feral plants that rarely grow from seed. Modern cultivars are bluer than classic types.

The evergreen foliage does not get much higher than half a foot, with thin and less impressive floral spikes that stand a bit higher in summer. It slowly spreads wider, but before it gets a foot wide, it will probably be going bald in the middle. Overgrown or balding plants can be dug and divided into new smaller plants in winter. Old foliage that gets shorn in the process is replaced in spring.

Finish Transplanting Before Winter Ends

90220thumbAutumn is for planting; and for good reasons. It is the beginning of dormancy for almost all plants, including evergreens. It precedes cool and rainy weather that inhibits desiccation until new roots are able to disperse sufficiently to sustain new plants. Some plants need to be in the garden in time for winter chill in order to initiate bloom. However, not everything should get planted in autumn.

Winter is the best season for some plants. Many summer blooming bulbs get planted in winter because they are likely to start growing prematurely and get damaged by frost if planted in autumn with spring bulbs. Some perennials that are slightly sensitive to frost may get planted after average frost season so that they can bulk up enough to be more resilient to frost by the following winter.

Besides new plants that are purchased from nurseries to be planted in the garden, there are plants that are already established in the garden that might need to get dug, divided, and then planted back into the garden, or shared with friends and neighbors. Some might need to be transplanted because they are crowded or in the way of something. These present a different set of variables.

Once divided and transplanted, grasses, New Zealand flax, lily-of-the-Nile, African iris and other stoloniferous perennials (that spread by creeping stems known as stolons) are more susceptible to rot than nursery grown plants, because so many of their roots get severed. Even if aggressively pruned while getting divided and transplanted, shrubby plants, like lilac and forsythia, are more susceptible to desiccation than nursery grown plants, simply because they lack sufficient roots.

If divided or transplanted through winter rather than autumn, plants get a few weeks of cool and rainy weather to settle and disperse their roots, but do not have enough time to rot or desiccate before the weather gets warm enough for them to resume growth and recover resiliency. Perennials that get cut back in the process spend less time looking shabby before new growth develops.

San Lorenzo River

P90210It may not look like much, but before all the rain started, the San Lorenzo river was shallow enough here to walk across. The water was clear and barely flowing. It is impossible to guess how deep it is now. It looks like cafe au lait, and is certainly flowing better than it had been. The watershed is less than a hundred and fifty square miles, so all this water is not coming from very far away.
The first picture above, of the San Lorenzo River flowing south to Santa Cruz and the Monterey Bay, was taken from the western of the two windows on the south side of the Felton Covered Bridge. Experts believe this to be the best of the four windows. My Mother has an old black and white picture of my older sister, my younger brother and I looking out from this window when were just little tykes. There was a railroad bridge out there a long time ago. Only concrete foundations remain.
The second picture below, of the San Lorenzo River flowing from the Santa Cruz Mountains beyond, was taken from the western of the two windows on the north side of the Felton Covered Bridge. The San Lorenzo River flows south on this side too!
It has been raining rather well here. Boulder Creek, which is at the far north end of the San Lorenzo Valley, gets more rain than most places in California, and far more than the rain shadow region on the inland side of the Santa Cruz Mountains. Local rain does nothing for the water supply of the rest of California, but is a good indication that snow is falling in the Sierra Nevada, where most of the water for much of the rest of California is stored in the snowpack.P90210+

Greenhouse Envy

P90209KIf there were lawns and fences in this neighborhood, the grass would likely seem to be greener on the other side of the fence. In this situation, the greenhouse probably seemed to be more comfortable than being left out in the storm. This tall Douglas fir tree dropped in to find out. It did not go well. What remains can be seen in the middle of the picture above, just to the right of the fallen fir, and in the close up of the picture below.P90209K+
Miraculously, the two coastal redwood trees that caught and guided the fir to a direct hit on the greenhouse also prevented it from destroying the associated house. Well, at least the redwood on the left did. There would have been less damage if the fir had fallen farther to the right. Regardless, a deck was crushed, an eave was destroyed, but the rear wall of the home was barely nudged. Not even the windows there were broken!
Falling debris punched a few holes in the roof, but without structural damage. The patio of the big building to the right was littered with debris that was easily removed. After limbs are removed from the damaged house, much of the carcass of the fallen fir will remain on the forest floor. It decays efficiently here.
Incidentally, this fir was about to be removed. It had been identified as too risky for the neighborhood. Although they are not visible in the pictures, there are a few other homes in the neighborhood. The cabin that I stayed in for more than a week is just beyond where the top of the fir landed. The stovepipe that is visible in the background of the second of my ‘Six on Saturday – Cabin Fever’ pictures from January 5 is the same stove pipe that is visible on the roof of the home that was nearly destroyed by the fallen fir. https://tonytomeo.com/2019/01/05/six-on-saturday-cabin-fever/P90209K++
(The stove pipe circled by the yellow oval just above the center of the picture above is the same stove pipe circled by the yellow oval just right of the middle of the upper margin of the picture below.)P90209K+++

Six on Saturday: Untimely Death

 

One of the more unpleasant parts of my work is condemning elderly trees. Redwood and oaks in our region can live for centuries, but none last forever. It is sometimes my job to determine if some of the oldest of oaks have deteriorated to such an extent that they have become unsalvageably dangerous to those around them.

What is worse than that is that there are so many dangerously deteriorated oaks and other trees that collapse before they get removed, and many do so before anyone notices how dangerous they are. Some structural deficiencies and instabilities are concealed to the most thorough of arborists. That is what happened with this big coast live oak, Quercus agrifolia, with a five foot wide trunk, that fell behind Felton Presbyterian Church. I had known for some time that the healthy canopy was heavy and exposed to wind. What I did not know is that the root systems was insufficient to maintain stability when strong wind blew against the healthy canopy while the soil was saturated. The insufficiency of the root system became apparent not only because the tree destabilized, but also because the minimal root system became exposed by the destabilization. There was no evidence of decay or damage within the root system, which are what typically contributes to destabilization.

1. It is amazing that this tree stood for as long as it did with such minimal roots.P90209

2. This is what those minimal roots supported for so long.P90209+

3. Healthy foliar growth on top of the canopy enhanced weight and wind resistance.P90209++

4. Damage was surprisingly minimal.P90209+++

5. This decay within one of the main limbs was a structural deficiency that did not contribute to the destabilization.P90209++++P90209+++++

6. (above) This is the same picture as #5. The red line is at the cross section of where a limb broke or was cut away many years or decades ago. Although the straightness of the zone suggest that it was made by a pruning cut, it is unlikely that the tree was pruned up as high as this section of limb was located, particularly so long ago. As the tree compartmentalized the wound, decay spread inward toward the center from the wound, in a typical pattern that resembles a section of a pie chart, which is marked by the yellow lines. Once it reached the center, decay radiated outward from the center, in a typical circular patter, which is marked by the blue circle. As the center of the trunk rotted and deteriorated, the necrotic zone between it at the original wound continued to rot and deteriorate. By that time this cavity developed, the exterior of the wound had already been compartmentalized by viable wood that did not decay.

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/

Tree Houseleek

60210The dark bronze and variegated varieties of tree houseleek, Aeonium arboreum, are so much more popular than the simple species, that the simple species with plain green foliage is now rather rare. The succulent stems do not stand much more than three feet tall. They get about as broad, and can get even broader as lower stems develop roots and grow into new plants. The succulent rosettes of foliage of well watered plants can be fragile to handle. Mature plants can bloom in spring with unusual conical trusses of yellowish or chartreuse flowers.

Attack Roses While They Sleep

8bd4This theme may be getting a bit redundant about now. There is just so much that needs to be done in the garden through winter for what will bloom in spring and summer. We plant new fruit trees, and prune mature ones. When we finish planting spring bulbs, we can start planting summer bulbs. Berries, rhubarb and grapes all get planted. With all this going on, it is also time to prune roses.

Like so many fruit trees through the past few centuries, modern roses were bred to maximize production. Instead of big and abundant fruit, they produce big and colorful flowers. Such enhanced production is more than overgrown rose plants can sustain. Pruning eliminates superfluous stems to concentrate resources into fewer but more vigorous stems, and flowers of superior quality.

Pruning also eliminates diseased, damaged, dead and dying stems; which are known as the ‘four Ds’. Foliage falls from the stems naturally through winter, but should be raked and disposed of because it can spread disease to new foliage in the spring. (Dormant fungal spores and bacteria overwinter in fallen foliage.) Foliage that clings to stems after pruning should be plucked away.

Pruning should ideally be done by the time buds begin to swell in late winter. Of course this is not as easy as it sounds in the mild local climate. Buds swell early, and may even start to grow before rose flowers from the previous season finish blooming! Modern ‘carpet’ roses and a few other shrubby types barely go dormant, but fortunately, they do not need such meticulous pruning anyway.

Hybrid tea roses need the most severe pruning, which leaves only three to seven canes approximately two feet high. These canes should ideally be unbranched below where they get pruned, and be spaced somewhat evenly around the center. Stout canes that grew last summer from the base of each plant are best. However, canes below graft unions are suckers that need to be removed.

Floribunda roses are pruned similarly, but can retain a few more canes. Some grandiflora roses are allowed to get significantly taller, with new canes on top of canes from the previous year, which may already be on top of canes from another previous year. It may take a while before they develop replacement canes from the base. Climbing roses likewise retain old canes for a few years.

Tree roses should be pruned as if the upper graft union is at ground level, so that canes should be about two feet high above the graft union. (Although, tree rose canes are usually pruned shorter.) Carpet roses and a few bramble types only need to be pruned low, but cane quality is not so important. They are not grafted, so can not develop suckers.