Roundup® doesn’t help maintain gravel

It took a few years to figure it out, but I’m ready to pronounce Roundup® and all other glyphosate herbicides useless, even counter-productive, in maintaining clean gravel.  Pulling weeds in flower is my most efficient way to control weeds in gravel.  

Gravel has to be maintained clean, or it disappears under plants and the soil that forms from organic matter and dust.  Plants add to the organic matter if they are allowed to die in place; they obviously detract from the gravel’s appearance.  Organic matter and dust can be regularly blown off, but plants are not so easy to move.

The key to controlling plants in gravel is reducing fertility, surface soil, and seeds.  Glyphosate adds to the first, as it’s a powerful crude organic fertilizer that preferentially grows broadleaf flowering plants because it’s high in nitrogen and phosphate.  But it also does not reduce seed load from the worst of the annual weeds, and makes them harder to weed out.  On the less-packed margins, it feeds worms that bring soil to the surface.

Annuals live to make seed, their only means of reproduction.  They grow a lot of root to support leaf growth when they are young; as they flower, they turn most of the mass of that root into stalks, flowers, and seeds.  Some can live off the water and proteins in their roots and leaves as the soil dries out, if you pull them and leave them lying on the ground, or if you kill their root tips with glyphosate. 

Some annuals, like bitter cress, miners’ lettuce, annual rye, and crawling knotweed, don’t die when hit with glyphosate; they immediately stop growing leaves and go to flower and seed, no matter how young they are, and they ripen those seeds.  When their root tips die because the glyphosate amino acid doesn’t fit in their new proteins, they use the good proteins in their remaining root and leaves to grow flowers and ripen seeds, which are therefore quite viable.

Plants crowd each other out with the help of bugs that eat smaller, stressed plants.  If hit with glyphosate, they don’t grow large and don’t crowd each other out, so one ends up with many very small weeds, hard to see and tedious to pull.  While the plants may not grow large, their aggregate mass still adds to the organic load and the seed load nearly as much as unsprayed plants. 

Unsprayed plants are a lot easier to pull, as they are larger and there are far fewer of them.  It is far easier to pull them in maturity than earlier, as the stalks are strong and easy to grab and the root is shrunken.  Nor does one have to pull the reduced root.  Most annuals in full bloom will not return if the top breaks off the root.

If your gravel is showing a lot of soil or is buried under plants and organic matter, it is best to cover it with fresh gravel, either crushed clean or small river gravel.  Avoid any “minus” crushed gravel, as it is full of fine mineral soil.  It’s a lot easier to blow leaves off of clean gravel than soil, as leaves really stick to soil.  Clean gravel grows a lot fewer weeds, as most need soil and a touch of sun to germinate.  It’s much easier to see the weeds and pull them as they flower.  And it looks really nice.  It’s far easier and much more gratifying to keep clean gravel clean than to clean up buried gravel.

How to grow big tomatoes, peppers, melons, and other heat-loving plants

There are three elements to growing productive tomato plants: a young plant; good soil; and warm soil.  The first is key; if you buy a plant that is blooming in its pot, it won’t grow for you, even if it is in good, warm soil.  Annuals like tomatoes stop growing and start blooming and making seed when their roots wrap around inside the pot and touch each other.  A root-bound plant that is blooming probably won’t grow much even if you bury the stem in soil; you’ll end up with a few fruit on a stunted plant. 

It’s nearly impossible to find a gallon plant in the stores that is not already blooming, and if you find one, a 4 inch plant will usually at least catch up with it.  Even 6-pack plants will beat gallon plants, which are grown for people who don’t know any better than to buy a big plant.  If you want to grow a big tomato plant, buy a small one.

Good nutrition is important; if your flowering weeds are not bountifully large, you should put down about 6 inches of compost on top of the soil and plant into it.  Do not mix it into the soil; worms will do it for you.  It will suppress weeds, and nutrients from the compost leach downward to the roots as they become soluble and available to the plant.  6 inches of good compost at least 3 feet wide will grow a big tomato plant even on bare rock or concrete. 

Warming the soil can be important if the summer is cool, and always helps the plant grow early in the season.  Covering the soil with mid-sized, relative flat river rock, of a size to easily move with one hand, will prevent evaporation from the compost, keeping it moist and preventing cooling; prevent weeds everywhere the soil is covered; and soak up and conduct heat during the day and release heat at night when it helps root growth.  I used to use 3 larger rocks around each plant, but now I’ve moved to a circle of the smaller rock at least 2 feet wide, after great results with watermelon last year.  Covering a whole bed with such rock will prevent cats from digging as well.

The rules for tomatoes also apply to peppers, particularly not using plants that are already blooming in the pots.  These are harder to find with peppers; this week, I was having a hard time finding 4 inch plants that weren’t at least budding, but the large 6-packs were good.

When it comes to the squash and melon family, as well as corn and beans, seed is the only way to go.  They really don’t like their roots messed with or any degree of root-binding.  If the soil is warm, they pop right up; if it is not, a started plant will just suffer in the cold.  If the bugs eat your plants, or the seed doesn’t sprout, the soil was too cold; replant.

Oak, pine, and walnut are good mulch

There are several gardening superstitions out there, regarding what leaves are not good for mulch.  Nearly all leaves are good for mulch, a notable exception being salt cedar, which are covered with salt.  Nothing grows under salt cedar.

Pine needles and oak leaves are thought to be acid, but they aren’t; their toughness can cause acidity, however.   Ph is determined by the movement of calcium in the soil and its balance with aluminum; calcium, which is alkaline, moves with water, while aluminum, which is acid, stays put.  In winter, calcium leaches down, and the surface becomes more acid.  In summer, calcium moves upward with evaporation, and the surface becomes more alkaline.  If the area is excessively watered or shaded, the surface stays acid; pine and oak trees and leaves shade the soil all summer.  When piled thick as mulch, however, the neutral Ph of the leaves overwhelms the Ph difference caused by shading the soil with them, and good soil happens as they break down.

Pine needles are quite useful.  They can be used as base mulch; roots will readily grow through them to soil.  They work well as top mulch, allowing water and light to reach seedlings while shading the compost.  They make good path cover as well.

Oak and tough evergreen leaves are particularly good for keeping weeds suppressed year-round in a shrub border or perennial bed.  Tough evergreen leaves like laurel or magnolia are also good to spread under tomatoes from mid to late summer, to keep the fruit off the soil; many evergreens drop their two-year-old leaves at that time of year.  Madrone is one of these, but their leaves are not as thick as most evergreens and readily break down.

Walnut is another leaf with a bad reputation; they are said to have a natural herbicide in them, juglone, that stops the growth of plants.  This is true, but the plants that they stop are seeds; started plants grow just fine in walnut leaves, as do oak, walnut, and other nut seeds. 

This makes them exceedingly useful; I use walnut leaves as a pre-emergent herbicide to stop weeds from sprouting in my perennial beds, and to keep blackberries and other bird-dropped seeds from sprouting beneath my huge sweet-gum tree.  They break down before winter is over; other mulch is needed to keep soil covered and moist.

If you have a bed full of walnut leaf soil that you want to start seeds in, spread an inch or so of compost in the bed, and sprinkle your seeds into it.  For larger seeds, put down and inch of compost, spread the seeds, and spread more on top.  This keeps the seeds from touching the walnut soil long enough for them to sprout and grow. 

Gather Leaves While Ye May

Leaves are beginning to turn, and soon they will fall.  Let them lie where they can do what they are supposed to do: feed the soil.  Clean them up off the places where they cause problems: roofs; gutters; pavements; paths; and lawns.  Spread them where they can do good, on soil.  As a last resort, send them to the composter. 

 Leaves will stop most small seeds from sprouting by keeping the sun off them; a couple inches of leaves will smother most small weeds as well.  Leaves will also suppress small garden plants.  You won’t get many pansy volunteers among oak leaves, and too many leaves can even smother the plants.    

To build good garden soil cheaply, pile your leaves a foot deep, well-watered and stomped down, and cover them with an inch or so of compost; this is the equivalent of 6” of good compost; both will grow big vegetables.  Softer leaves are better for this; sycamore in particular will not readily break down when piled, even under compost, unless they are first chopped up in a shredder or leaf vacuum.  Tough leaves like sycamore and magnolia are brittle and bust up into little bits going through the machine.

In my work, I use leaves as base mulch only if they are on site and readily available; otherwise I use straight compost, from 2” for flowers and shrubs to 6” thick for vegetables, and cover it with light top mulch.

Compost, whether piled thick or spread thin on leaves, will dry quickly in the sun and must be covered with a light mulch of bark, wood chunks, or evergreen needles, just enough to hide it from the sun.  Dark, half-composted wood mulch has been my favorite for a while, but only one composter makes it and the supply is not dependable.  Chipped tree trimmings can be acquired through tree-trimming outfits, who keep a list of nearby places to dump them.  Shredded and nugget bark is readily available from landscape supply places; avoid fine or un-sifted bark, as excessive bark dust kills soil organisms with its natural preservatives.  Pine needles are free and renew their supply every year; their downside is a tendency to poke fingers and slide off beds, and they are difficult to spread neatly among plants.

Paths may need mulch of their own; wood chips, shredded and nugget bark, or pine needles work well.  Wood chips are most effective at suppressing weeds; nugget bark lasts longest; shredded bark clings best to slopes.  Pine needles are free and renew themselves.

Leaves are messy, and have a tendency to spread and blow.  Edging your beds with rocks can contain the leaves and give a finished, permanent look to your beds.  Choose rocks at least the size of a football; anything smaller is too delicate to stay in place or hold anything.  They should have flat bottoms and be laid end-to-end, sloping back, for stability.

Seeds v. Starts 2: Fall planting

Fall is the best time to plant many things in Southern Oregon, including trees, shrubs, perennials, wildflowers and cool-season vegetables. Our relatively mild winters allow roots to grow throughout the winter, and the plants take off in the spring. Many plants drop seed over the summer which comes up in cool, wet fall weather; some seed needs to be stratified over the winter by soaking in cold water, freezing and thawing, so fall scattering results in spring sprouting. It's good to save some fall-sprouting seed for spring, however, as a hard winter can kill seedlings that sprout in the fall.

Here again, seeds are generally superior to starts for vegetables, growing faster and quickly surpassing most started plants. Most sprout readily, except for store-bought seed of cabbage family plants: cabbage; broccoli; cauliflower; and mustard; and spinach family plants: beets; spinach; and chard. Store-bought seed of these plants does not germinate well when broadcast, but seed that forms in your garden or nearby sprouts readily. Started plants rarely grow to full size, unless they are bought exceedingly fresh, before the plants get root-bound. But they are a way to get good seed to start in the following season or year.

Last fall, I special-ordered some Flat Dutch cabbage for making poultices, as most cabbage in stores is too tightly folded to easily make poultices; half the head goes to salad or waste. Some plants grew very well. One of those flowered this spring, but several made large, loose heads this summer instead, and will likely bloom this fall or next spring. It will be interesting to see what the seed from the single early bloomer will do next year: head up or go to seed immediately?

Broccoli starts bought this spring, being focused on flowering, went to seed quickly, too small to make good florets; the seed should make good plants this fall, and florets next spring. Cauliflower didn't make it through the winter. Spring-bought, root-bound Early Jersey Wakefield, a loose cone-head cabbage, is making small heads on small plants, and should bolt and bloom sometime in fall or spring.       

And I discovered something new this spring: cabbage can grow from the core of a head. When I had to make a lot of poultices early this spring, I was left with a lot of tight partial heads that got too old to make sauerkraut, so I threw them in the garden, where they got buried in the leaves I was building beds with. Some grew roots and flowered! When I later got a rare cone head that I could use to the core, I put the fist-sized core with its last few leaves in the mulch, base down, and it grew. I pulled the tight-head plants so they wouldn't breed with the new one. But it didn't bloom, being planted later; it still hasn't bloomed, but it made a little head on one side of the stalk. 

Pruning Shrubs Can Be Easy

The easiest and best way to deal with an ugly or too-large shrub is to cut it to the ground.  It will do one of two things: die, or grow back young and pretty.  Either is an improvement.

Don’t expect it to die; this is very rare, unless it is an evergreen conifer, like an arborvitae or juniper.  If you cut all the green off an evergreen conifer, it will die; it has no storage in its roots.   This can be a good thing.

If you cut a deciduous shrub to the ground in mid-summer, it may come back very small, as its roots are emptiest at that time.  If you cut it to the ground in mid-winter to early spring, it will come roaring back, as its roots are full of food at that time.  If you cut it to the ground right after blooming, no matter what time of year, it will come back smaller than otherwise, as a plant expends a lot of energy in blooming.

If you cut a broadleaf evergreen, like a rhododendron, to the ground in midsummer, it will grow back; its roots are full of energy because it hasn’t been living off root storage all spring, putting on growth, like the deciduous shrubs, but it has more root storage than a conifer.  If you cut one to the ground in spring or right after bloom, it may disappear entirely; blooming takes a lot of energy, and its root storage runs low in winter and early spring.

Sometimes a large shrub is simply growing into the way and you don’t want to cut it down.  Chopping off the branch at the point where it begins to get in the way will ruin its form and have it growing right back into your way.  Cut the branch off at its base--or as far back into the shrub as you can reach, if it’s a thick evergreen conifer. 

Some people insist in hedging, which is high-maintenance in the fast-growing shrubs that are chosen for most hedges; they must be trimmed several times through the growing season.  Slower-growing shrubs, like camellia and azalea, can be trimmed once a year and preserve their shape.

Hedge trimmers give a plant a haircut, but it’s a bad haircut, with cut ends and leaves sticking out all over.  The shrub also immediately grows out from the buds below those cut ends and need trimming again.  It is better to prune the twigs that stick out too far one at a time, longest first, cutting them back to their bases or even below, down to the next twig, eliminating the clusters of branch bases that build up in the top of most hedged shrubs and catch falling leaves and other debris.  It won’t be as tight as a hedge given a haircut, but it will look prettier, be healthier, and go longer between trimmings.

Gardening is easy, if you do it naturally.

Seeds v. Starts 3—Trees and Shrubs

Our Landscape Management teacher at RCC told us that a small tree will outgrow a large tree within just a few years, and for the most part I’ve found that to be true: a gallon tree will generally outgrow a 5 gallon or larger tree within 5 years.  An exception is small, slow-growing trees like weeping Japanese Maple.  Faster-growing trees become quickly root-bound, and the root balls on larger trees are smaller in proportion to the size of the tree than on smaller trees.

Another exception is exceedingly small trees, such as the ten trees given “free” by the Arbor Day Society in return for a $10 “donation” or conifers sold by state forestry department for 50 cents or a dollar apiece, which are lucky to survive their first year.  Even under good garden conditions, such trees often have less than 50% survival.  They may well outgrow larger trees if they do survive, but they won’t outgrow a seed that starts within a year or two.

A seed-started tree that grows where it sprouts will always outlive and outgrow a transplant in the same spot, because its roots are never broken or distorted by transplanting.  The very small conifers sold by the state are grown in narrow tubes, in which they grow roots longer than the tube that fold up and down within it; they have to be cut to be planted in a shovel-deep hole.  They are rarely spread out over a cone of soil in the planting hole, and even if they are, they can never match the form of roots that grow without disturbance.

The best time to plant either trees or shrubs in Southern Oregon is fall, as the roots can grow all winter and spring before the summer heat.  This goes double for most tree seeds, as most of them require stratification, soaking in cold water or freezing and thawing, to crack their seed coats and get them to sprout.  The seeds that need to spring planted, like Amur maple or box elder, are obvious, as they hang on the tree until spring.

Some seeds require heating from a fire or being eaten by birds to sprout; these are not so easy to plant by seed.  Madrones are always a gift from the birds, as they need their stomach acid to sprout, don’t survive transplanting at any size, and can’t live in a pot.  Fortunately, the birds spread them widely, particularly under trees and along fences.

Shrubs follow much the same rules as trees, but people are only likely to want one to grow fast in the beginning, to fill the space allotted to it.  After that, the problem is often keeping it within that space.  Here again, a 1-gallon shrub will fill the space faster than a 5-gallon shrub, and be healthier thereafter.

And here again, it pays to buy a larger plant if it is slow-growing, or if its root system is shallow and fine, rather than deep and thick.  Blueberries are a case in point.  They don’t root more than about 6” deep, even in a deep pot.  Their fine, spongy roots do not get root-bound, and they grow slowly.  So buy the 3-gallon blueberry; it will give you blueberries that much sooner.  They are an almost perfect landscape shrub; they grow slowly, need no pruning, and have great fall color, and provide fruit that you can leave for the birds if you are lazy.

Beat Black Spot; Crown Your Roses

     Right now is prime time to crown your roses.  To get rid of black spot for the summer and make them grow their best, they must be cut to the crown, the solid knotty base below the stems and above the roots, and allowed to grow fresh canes. 

 

A Betty Boop rose, crowned mid-summer and blooming heavily in September

Cutting them off a foot high, the conventional way to treat roses in mid winter or early spring, leaves black spots on the stems and keeps the infection going.  The same goes for taking the old leaves off as the new leaves start to grow in; the new growth will be spotty before the new roses bloom. 

This applies mainly to tea roses that are not climbers.  Climbers bloom on second-year wood, and you will lose a year of bloom, but you can cut individual canes after they bloom.  Rosa rugosa doesn’t get black spot or molds, but should be crowned and allowed to regrow when it gets too large.

Josephine County, with its mild, wet winters and cool, rainy springs, is a hot-bed for black spot and other fungal diseases.  In Grants Pass, with many roses neglected entirely, photinias spreading the same diseases, and a city-owned pear orchard that was neglected for years and is in the process of being cleared, they are epidemic.

One can crown a rose anytime, and I have been doing so as soon as I saw black spot or mold for the last few years.  I have even crowned them in late fall and midwinter, but that slows re-growth in spring, as the plants get no warmth from the air and must wait another month or two for the soil to warm.  So this year, I crowned them after they broke dormancy and started to grow in early spring, which comes earlier here than most places at this latitude, in mid-February.  Some are already re-growing, only two weeks later.

Joan's rose, about two months after a February crowning

Cutting to the crown means cutting each cane to its base.  Roses hate any kind of dead wood, which blocks new sprouts, and branches that grow from stubs do not grow as well as a cane from the crown.

Crowning roses sometimes means going underground, when they are planted too deep or sink into rotting organic matter, like a stump.  The latter happened to one of my dad’s roses, which I had been cutting only to the ground for several years; it kept growing back smaller and more spindly from such treatment, as its stems were growing from underground stubs, not the crown. 

This year, I was determined to cut all roses to the crown, and dug to find it.  The top of the crown was a good 8 inches below ground, and it went a foot deeper, with thick “arms” reaching for the surface as the years went by, and roots reaching up around it.  Not wanting to dig that far every year, I dug it out and planted it with the crown above ground.  It should live; roses are tough.  (It didn't.  That's all right; roses are cheap.)

You can’t hurt a rose by cutting it, just by not cutting it sufficiently.  Go all the way to the crown for best re-growth and to beat the black spot.  Do it as the new leaves grow in early spring, and you can have clean, pretty roses all summer.  If you don’t, you can do it again as soon as black spot or mildew shows up.  The tea rose is a royal pain; it needs to be crowned.

Rycke Brown, Natural Gardener    541-955-9040   rycke@gardener.com

How to grow Blueberries in S. Oregon

Blueberries can be tricky to grow in Southern Oregon.  They like to grow in full sun, but their roots demand cool, loose, rich, moist soil, which doesn’t naturally occur here.  So you have to make it.

They don’t like being planted in soil; they like to be planted in 6” of compost on top of the soil.  Young blueberries have a spongy root system only about 4-6” deep.  As they mature, they put down a deep root, but for several years the whole root mass is easily transplanted.   As the compost is worked into the soil by worms, the soil is worked upward into the root mass.  If you plant other “gallon” (#1) potted plants into plain compost, they will eventually be left high and dry as the compost evaporates; blueberries spread their roots through the compost and sink into the soil.

That compost will dry out fast if it is left uncovered, so cover it well with loose, coarse mulch which will shade and protect it.  Pine needles, walk-on fir, or ¾” nugget bark work well; avoid fine bark, which kills soil.  Blueberries need live, loose soil to thrive.

But those roots will be coolest and happiest if they are covered with a green ground cover with roots that grow through the blueberry roots to the soil beneath or grow on top of them.  Lysimachia, also known as Creeping Jenny or moneywort, and small sedums grow on top; violets and strawberries grow through.  Sedum is slow growing but easier to control, and is easily peeled off the soil and transplanted in large mats if you can find them.

Some ground covers grow in the same root zone and compete rather than cooperate with your blueberries.  Blue star creeper killed a huckleberry in one of my yards.  Sweet Woodruff has similar spongy roots and directly competes for space.

Water is critical to blueberry growth and survival.  They can take a little dry, but too much too often will make them unhappy and eventually kill them, one reason why they like their roots covered with mulch and ground cover.  They can take a lot of water in winter; the biggest, oldest bushes I’ve ever seen were growing next to a pond that flooded them most of the winter.  If practical, site them in the wettest spot in your yard that gets sufficient sun but is not flooded in summer.

Southern Oregon is very hot in the summer.  Northern blueberries might prefer a little afternoon shade.  Southern rabbiteye blueberries, available in catalogs and some at Bi-Mart, can take our heat better.  Northern turn brilliant red in the fall and lose their leaves; southern turn various colors in pink, yellow, and red and keep many leaves through the winter.  Both types cross-pollinate; all bloom around the same time, regardless of when they ripen.   Southern tend to bloom and ripen later, over a longer season.