Mulch Is Imitation Of Nature

91113thumbEvery living thing in our gardens came from the wild somewhere. A few plants might be natives trying to adapt to synthetic landscapes. Some might be from similar climates. Some are likely from very different climates. Even houseplants came from the wild somewhere in the World. Regardless of their respective origins, in home gardens, all plants want to behave as they would in the wild.

Many plants want to defoliate at this time of year. Even some evergreens want to shed some of their old foliage before winter. Some perennials die back to the ground. Most summer annuals are already dead. There is an abundance of deteriorating organic material getting discarded by the plants that produce it. In the wild, all this detritus would naturally fall to the ground and decompose.

That might be a problem in parts of our refined landscapes. Fallen leaves must be raked from lawns, decks, pavement and various other flat spaces outside. If left too long, they shade out lawns, ground cover and bedding plans. Fallen leaves can stain decking and pavement too. The worst diseases of roses and fruit trees overwinter in fallen infected debris that does not get raked away.

Unfortunately, raking the mess of autumn away deprives the plants that live in the garden of the abundant decomposing organic matter that they expect to be delivered this time of year. The soil is left exposed and uninsulated, allowing temperature and moisture content to fluctuate more than they would naturally. Nutrients are not replenished as readily as they would be from decomposition.

Mulch, which can be applied at any time of the year, is quite seasonably appropriate in autumn. This is when plants expect decomposing organic matter to arrive from above. Mulch compensates for the loss of what we consider to be a mess, but what plants consider to be an important component to their natural ecology. It gives them what they want, but is neat enough for refined gardens.

The best mulch for the job just might be fallen leaves that were raked last year and composted, perhaps with other debris from the kitchen and garden.

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Horridculture – Fake Media

P90911This is no way to get the dirt on someone. There is no dirt involved. If there were, it would be referred to as ‘soil’. ‘Dirt’ is a term used by those who do not know any better.

Anyway, this is about the media that plants are grown in. It might be called growing media, potting media, potting mix or simply potting soil. Some in the horticultural industries might say that, because it is assembled from a variety of components that do not naturally occur together, growing media is synthetic. Because it lacks real soil, most of us refer to it simply as soilless.

Now, I am aware that not all media are created equal. The medium that we grew citrus in was much sandier than what we grew rhododendrons in. It was purchased already mixed specifically for citrus, and ready for use. The medium for the rhododendrons was mixed on site, with more coarsely shredded fir bark (from local mills), less sand and a little bit of perlite.

What I was not aware of, was just how perishable potting media purchased from retail garden centers are. Rather than drive out to the farm for a bin or two of medium, I purchased a bail of common ‘potting soil’ from a garden center about two years ago. I just happened to be there to pick up something else. The cost seemed worth avoiding an extra trip to the farm.

It actually was worth the cost. It did what I needed it to do for a time. The problem I am noticing now is that plants that were not planted or canned up (into larger cans) soon enough are now lacking the volume of medium they need. They need to be stuffed, which involves sliding them out of their cans to add a bit more medium to set them on top of, back in their cans.

The potting soil decomposed too readily. It is as if it rotted into muck that was rinsed through the drainage holes with watering. I suspect that there was more to the medium that the typical simple components. It probably contained significant volumes of compost derived from recycled greenwaste. I certainly have no problem with that. I just would have liked to know about it.

This little American persimmon seedling can stay in this half empty can until winter dormancy. Once dormant, it can be canned into a #5 (5 gallon) can, to resume growth next spring, before it even realizes that it is lacking medium. It will get a happy ending.

To Mulch Is Not Enough

60727thumbMost plants would prefer the real thing; how they do it in the wild. They drop their leaves, flowers and twigs. Deciduous plants do it mostly in autumn. Evergreens might spread it out through the year. The debris accumulates on the ground below, and decomposes at about the same rate as it accumulates. There is no one there to clean it up. Yet, the natural ecosystems know what to do.

The plants that produce the debris use the nutrients produced by its decomposition. So, with the help of the many microorganisms in the soil, they recycle their own trash. To exploit this resource most efficiently, feeder roots tend to congregate near the surface of the soil where the nutrients are. Because the debris also insulates and shades the soil surface, roots are comfortable there.

Densely forested ecosystems produce the most debris. Many smaller plants in such ecosystems may disperse their roots exclusively into decomposing debris without reaching into soil below. In desert ecosystems, where such debris is minimal, roots are mostly dispersed much deeper to avoid the hot and dry soil surface. They wait for recycled nutrients to leach to them through the soil.

Redwoods, cypresses, many pines and most eucalyptus produce unusually thick layers of debris that decompose slowly. This technique inhibits or prevents the germination of seeds of potentially competitive plants. So, in other words, these trees and other plants had this, as well as moisture retention, soil insulation and nutrient recycling, all figured out long before we knew about mulching.

After we put so much work into raking and disposing of foliar debris that would otherwise accumulate in our gardens, it is ironic that we sometimes need to apply seasoned mulch to compensate for the lack of organic material on the surface of the soil. (Unseasoned mulch draws nitrogen from the soil to sustain its own decomposition.) It does more than merely improve the appearance of otherwise exposed soil. Mulch helps unnatural landscape environments function a bit more naturally.

Six on Saturday: Mudslide

 

With all the rain, it was no surprise. Mudslides are somewhat common here, and they sometimes close roads. In fact, we were sort of expecting a small mudslide almost in this particular spot right when we got the call about it. The only slight surprise was that it was right next to where we expected it to be. The cliff that we expected to make this sort of mess was still intact under the tarps put over it to deflect some of the rain.

Fortunately, it was a small mudslide that blocked only one lane. We were able to direct traffic through the other lane while the blocked lane was cleared of debris by a small bulldozer.

The top of the cliff slid to the bottom along with a stump of a Douglas fir that was cut down many years ago. The Douglas fir was cut down so that it would not destabilize the soil that it was rooted into as it moved in the wind. However, The soil was destabilized as the Douglas fir roots that held it together decayed. This is actually a common dilemma, since trees sometimes need to be cut down before they cause such problems, but the death and decay of the roots of such trees ultimately cause the same problems.

The sorts of trees that could be coppiced do not do so well in the dry soil on top of cliffs. Otherwise, we could plants willows, cottonwoods or something of the sort, and cut them down as they get too big, without killing the roots. They would be happy to regenerate and continue the process. The sorts of plants that prevent surface erosion do not do much to stabilize the soil. Otherwise, we could put something as simple as freeway iceplant (Carpobrotus chilensis) on top, and let it cascade downward over the unstable area.

1. It was nothing too serious, but just enough to block the inbound lane. Tarps over the cliff that we expected to make this sort of mess are visible above the retaining wall just beyond. My work pickup in the lower right corner of the picture blocked the inbound lane with its headlights and hazard flashers on. I directed incoming traffic around it into the clear outbound lane as it was available. The young man off in the distance moved his pickup out of the outbound lane, and also directed traffic accordingly. When necessary, he stopped traffic while incoming traffic used the outbound lane. We communicated by radio and hand signals.P90309

2. This is the stump of the Douglas fir that was cut down so that it would not dislodge the soil and cause a mudslide. A decayed stump of a smaller madrone tree is to the right. Their rotting roots and the English ivy were insufficient to stabilize the top of the cliff.P90309+

3. These significant mudstone boulders on the far side of the road could have done some serious damage to a car if one had gotten in their way.P90309++

4. That is where the Douglas fir stump came from, just to the left of the drainage pipe. It did not get very far. That is it at the lower left corner.P90309+++

5. We arrived about ten. By noon, there was not much evidence of what had happened. We left the cones because the road was slippery with mud.P90309++++

6. This is supposed to be a gardening blog, so here is an unidentified fern that witnessed the whole ordeal from a stable portion of the same cliff. There is slightly more flora to this story than two dead stumps and a bit of ivy.P90309+++++

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/

Mulch Suits Autumn Quite Naturally

81114thumbIt is silly for us to think that we know more about gardening that the plants who live out in the garden full time. We can help them along by giving them a bit more of what they need to survive, such as water and fertilizer. We can prune them to help them concentrate their resources into bloom and fruit production. Through it all though, we really need to be observant of what they do naturally.

For example, we water many plants through dry summer and autumn weather because we know that they are naturally endemic to climates that provide a bit of rain throughout the year, and that they can get dry without it. We fertilize them when they are actively growing because we know that is when they want it. Most deciduous plants get pruned in winter because they are dormant then.

This time of year, deciduous plants are defoliating in a very obvious manner. Evergreen plants are more subtle about shedding some of their foliage. Defoliation and shedding happens this time of year because plants do not need so much foliage, if any, when there is not so much sunlight for foliage to exploit. The days are shorter, and the sun is at a lower angle, so sunlight is less direct.

There are other reasons why winter defoliation is sensible. It makes deciduous plants more aerodynamic, and less likely to be damaged or blown down than they would be if they kept their foliage for wintery winds to blow against. Likewise, when the weather gets frosty, defoliated deciduous plants leave little to get ruined. What does all this suggest for seasonal garden chores for autumn?

Mulch, which can be spread at any time, is particularly timely for autumn, because that is when the garden expects organic material from above. Just like fallen leaves would do in the wild, mulch settles in through rainy winter weather, and helps to retain moisture after the rain stops next spring. It inhibits weeds that will want to grow as soon as the rain starts, and insulates perennials that grow slower or go dormant when the weather gets cooler. Mulch helps an unnaturally cultivated garden do what it wants to do naturally.

Happy Easter!

P80401Happy Easter!

This is one of those holidays when no one should work, which is why I wrote this a few days ago, and scheduled it to post today. I hope you are not reading this today. You have more important things to do. Lent and the forty days of fasting that goes with it are over, so you can eat all the Easter eggs and anything else you want.

The only work that should be done today are chores that can not be delayed until tomorrow. With the weather warming (at least in our region), watering might be one of those chores. For most parts of the garden, this might be the first watering since autumn. Although the rain has been meager, cool weather had kept things damp until now. Resuming watering is typically an easy task. It sounds simple enough. Water is water – right?

I get all sorts of unexpected questions in my work. In autumn, I sometimes get asked about trees that were planted in spring or summer that are suddenly turning yellow and dropping leaves; and must explain that the seemingly sickly trees are merely deciduous and defoliating for winter, which can be a major disappointment if evergreen foliage was needed. Then there are the questions about the five pound kumquat that is actually a shaddock fruit on an overgrown sucker (understock from below the graft).

About this time, many years ago, I got a call about a sad #5 (5 gallon) pistache street tree that had been planted while bare during the previous autumn. The client who planted it wanted to do what was best, so planted it in autumn so that it could settle in slowly while dormant through winter, and get an early start dispersing roots in spring. Generous rain that year provided more water than the tree needed through winter. As the rain ran out, and the weather warmed, buds swelled and began to pop. The client who planted the tree was very careful to water it when she thought it was necessary, but the new foliage immediately started to get discolored and distorted. Her remedy was to give it more water, but the health of the tree continued to decline as quickly as it was trying to foliate.

I asked all the typical questions about the tree, but only determined that it was not lacking water, and probably was not getting too much water. The symptoms exhibited by the foliage suggested soil saturation and poor drainage, but the soil drained well, and the roots seemed to be firm. I was baffled, until the client mentioned something very unexpected. I had to ask her to clarify.

She loved the tree so much that she wanted to give it the best water she could obtain. Every day, on her way back from downtown San Jose, she stopped at the Cathedral Basilica of Saint Joseph to procure a gallon of Holy Water to water it with!

That was a new one. I then had the sad duty of explaining to her that her devotion to the tree was what was killing it. The Holy Water that she had so diligently been giving it was saline. After Holy Water is blessed, some gets stored for upcoming baptisms, and the rest gets blessed salt mixed into it, mainly for sanitation. It was this salinity that was so toxic to the tree.

After a lot of fresh water was rinsed through the root system, the tree started to recover almost immediately, and eventually resumed healthy growth. The client telephoned the following autumn as the tree was coloring to inform me that it had been restored to good health, and grown through summer as if nothing had ever happened.

Fertilizer

P80325‘Fertilizer’ is a polite term for ‘recycled vegetation’.

‘Recycled vegetation’ is a polite term for something else.

This is not a synthetic type of fertilizer that gets tossed about or poured on. It gets added to compost and allowed to compost some more before being spread out as a mulch over the surface of the soil, just before chipped vegetation gets dispersed over the top. Alternatively, it sometimes gets mixed into the soil. It is quite useful. You can’t beat the price.

It is recycled differently from the compost or chipped vegetation (from a brush chipper). It is recycled through a horse, or more specifically, two horses. As the picture above suggests, it begins at the front of the horse, and ends at the rear of the horse, which is not pictured.

The horses happen to be quite efficient at recycling vegetation. They do it all the time. They are probably doing it right now. I would describe the process, but I do not know how it works.

Three times weekly, on Mondays, Wednesdays and Fridays, some poor sucker must go to where the horses live and work to collect the binned ‘fertilizer’, and deliver it to the compost pile. By the time it gets mixed into the compost, and composted more, it is not recognizable. Otherwise, it might be a problem in the parts of the landscape where it gets dispersed with the compost.

The landscape seems to like it. Only a few plants with special needs get any sort of synthetic fertilizer.

This sort of recycling is not new technology. It has been around as long as horses have been serving humans. In fact, it was not even invented by humans. Horses were doing it long before humans merely discovered, refined and took the credit for it.P80325+

Na2CO3•NaHCO3•2H2O

P80321Trona

That is what this seemingly disorganized jumble of letters and numbers represents; the chemical formula for the mineral known as trona. It is what a certain small town in the very northwestern corner of San Bernardino County is named for. Trona is one of a few minerals mined and refined there. Apparently, not much else happens there.

Trona the town is about as out of the way as one can get in the contiguous United States of American. Death Valley to the northeast at least gets tourists. Not much flora survives in the hellish summer heat and caustically saline soil. The athletic field at Trona High School is famous for being grassless dirt. Even the now defunct golf course was dirt. Roofs are more important for providing shade than for keeping the four inches of annual rainfall out. A leaky house is more likely to petrify before it rots. The inertly arid air, roasting heat and acrid drifting minerals seems to sterilize and embalm even abandoned houses. The Google Satellite image shows how boringly uniform the factory tract houses are. Many are now abandoned. Some are missing.

Why am I mentioning Trona here? Because horticulture is so limited in Trona. There might not be many better places in America for a horticulturist who lives amongst dense forests of the tallest trees in the world to go on vacation! There are so few distractions! The vast desert extends for miles in every direction, with only a few plants surviving in home gardens in town. The satellite image shows how empty the gardens are. A single lawn can not be found. Even artificial turf is notably absent, perhaps because no one wants to go outside in such horrid weather.

I suppose that I will never know until I go there.

Pots And Pans Need Cleaning

30918thumbThis is getting to be cliché. “While they are dormant through winter”, plants tolerate all sorts of abuse that would offend them at any other time of year. It applies to planting bulbs and bare root plants. It also works for pruning deciduous fruit trees and roses. It is a predictable seasonal pattern. Most winter gardening is contingent on dormancy. Processing potted plants is no exception.

Plants that have gotten too big for their pots should be replanted into larger pots. Any circling roots should be severed, just as if the plants were going into the ground. Unlike planting into the ground, potted plants require artificial media, known simply as ‘potting soil’. If larger pots are not an option, overgrown plants must at least be pruned to stay proportionate to their confined roots.

A plant that has been in a pot long enough for the media to decompose and settle might benefit from being ‘stuffed’. This involves removing the root mass from the pot, adding just enough media to the pot to support the root mass at the desired level, replacing the root mass on top, and then adding more media around the root mass to fill the pot. Exposed surface roots can be buried too.

Many overgrown succulents (not including cacti) can be replanted lower instead of higher. If settled, more media can be added on top. If all the foliage is clustered on top of bare stems, the stems can be cut and ‘plugged’ as new plants into pots of media, while the old roots and basal stems can be left to generate new stems and foliage. Newly plugged stems will generate roots by spring.

In the processes of potting, stuffing and plugging, while pots are empty, it would be a good time to scrub away mineral deposits from the bases and inner rims of pots. These deposits tend to accumulate just above the surface of the potting media, and where pots sit in water that drains from them. The pans or saucers that contain drainage water also accumulate mineral deposits. While plants are being processed, they can be groomed of deteriorating foliage and other debris.

Planting Cool Season Cover Crops

71129thumbTraditional horticultural technology that was so common in the orchards, that were likewise more common, was more practical than so much of what we do in our modern home gardens now. Orchardists got good insects to take out the bad insects. They got mulberry trees to distract hungry birds from maturing apricots and prunes. They even got weedy annuals to control other weeds.

Once it got established, mustard grew wild under many orchards. It self sowed so efficiently that it did not need to be sown. It grew fast, and shaded out other nastier weeds. Anyone who wanted to pick greens could take all they wanted without setting it back. It was sometimes tilled in early, or cut early and left on the surface as mulch, but was probably most often left to die back naturally.

Besides controlling weeds, the mustard improved the soil and kept it friable, both by dispersing roots through it, and also by decomposing into it. Other types of cover crops help limit erosion through winter, or improve soil fertility. All are very easy to plant and grow, and almost all get all the water they need from rain through winter. They only need to be cut and tilled when they are done.

Of course, they are all ‘done’ at different times. Orchard mustard that never gets cut or tilled is never really done. It just perpetuates itself. Cover crops in home gardens are done when we say they are done, before the space is needed for something else. Some should be cut before self sowing and becoming more a weed than a cover crop, whether or not the space is needed right away.

Cover crops get planted by simply broadcasting seed onto freshly tilled soil that will not be used for anything until next year. After seed is broadcast, the soil can be raked lightly to cover the seed. If it is not watered right away, the rain will take care of it. Fava beans, oats, barley, millet, clover and annual rye grass are some of the more familiar cover crops. Sesame and sorghum are rare.

Freeway iceplant and old varieties of common geranium (Pelargonium X hortorum) can function as prettier perennial cover crops. The iceplant can be cut from established colonies and plugged as short cuttings about four inches long. When geraniums get cut back, the pieces can likewise be processed into cuttings. Unlike annuals, these would get removed when their space is needed.