Troubleshooting Plant Problems

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Troubleshooting is a form of problem solving. And whether it’s a car problem, your smart phone, an irrigation system or yellowing leaves on a plant the goal is to solve it and make the product or process operational again. When you eliminate the potential causes of the problem hopefully the solution restores everything to its working order. Sounds like something Sherlock Holmes would say and it’s sometimes easier said than done as we all have experienced.

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sunburned heauchera leaves

A few weeks ago I received a text with pictures of some plants with brown spots and asked what I thought might be the problem with their plants. This was after the heat wave we experienced and after asking a few questions about irrigation, location and how long the plants had been in the ground, I determined that the plant leaves had been burned in a pattern consistent with the location of the beating sun. At this time of year plants are growing wildly and need a good soak moistening the entire root zone. The solution: Better to water deeply less often than lightly which might not reach all the roots.

The subject of how much fertilizer and what kind came up in another troubleshooting email thread between some fellow horticulturalists. The issue was whether to use another round of organic high phosphate fertilizer in order to encourage bud development on a notoriously short-season tree dahlia. After some lively discussion we decided that the early spring application of rock phosphate was sufficient. Sometimes adding too much phosphorus may actually hurt a plant by preventing the uptake of other nutrients which must also be available to the plant in order to prevent unexpected deficiencies to appear. A balanced fertilizer containing all three nutrients- nitrogen, phosphorus and potassium-was recommended for the remainder of the season.

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yellow leaves on lemon

Then there were some problems in my own garden. Well, it seems I am always trying to solve something with plants, pests or critters but this was with my lemon tree. At first I was perplexed when the older leaves of my lemon tree started turning yellow a couple months ago. The new growth looked fine so it wasn’t an iron deficiency where the young leaves display green veins along with the yellowish color.

It wasn’t a nitrogen deficiency either where the mature leaves slowly bleach to a mottled irregular green and yellow pattern, become entirely yellow and then are shed while the discoloration spreads to the younger leaves. I had fertilized in March with an all-purpose balanced fertilizer. Citrus are heavy feeders and require a steady source of nitrogen, the ideal citrus fertilizer having a ration of 3:1:1 (N:P:K)

After eliminating other mineral deficiencies or overwatering as the problem I decided that my lemon was simply dropping interior leaves which is normal after winter but I wanted to trouble shoot all potential causes to be sure citrus greening wasn’t the culprit. If it had been this deadly disease the leaves would have exhibited an asymmetrical pattern.

To quote Sherlock Holmes “Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth.” I’ll try to remember that when I’m troubleshooting my next problem in the garden.

California Natives for Containers

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My ambitious plans to augment this garden here in Bonny Doon with California natives and colorful plants to attract birds and wildlife is not turning out exactly as I’d pictured. I thought that I had licked my gopher problem by planting everything in baskets. Not so, now they just come up next to their plant of choice at night and eat whole thing from the top, dragging the rest down into their neat little hole while leaving the root still snug in its basket. Hopefully, some will regrow from the roots.

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Western azalea

But I’m not giving up on planting for the birds and bees. I’ve got plans to increase my container garden collection. Gardening in containers is easy. I can control the soil, water and light and the gophers can’t undermine my efforts. There are a lot of California native plants that do well in containers and I’m going to place them where both the birds and I can enjoy them.

For some of my largest containers I’ll choose from natives like Western Azalea, Deer Grass, Chaparral Pea or Giant Chain Fern. Any of the taller growing ceanothus and manzanita would look great too by themselves or combined with smaller growing plants.

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Mimulus ‘Jelly Bean Gold’

For small to medium containers I can use Conejo Buckwheat, Hummingbird Mint, Penstemon Heterophyllos, Mimulus, Woolly Blue Curls or Coastal Daisy, These combine well with colorful Lewisia, Dog Violets or Wild Strawberry.

I might combine a madrone with a Canyon Gray Coastal Sagebrush – Artemisia californica – which grows about a foot high and will trail over the side of the container adding beautiful gray color to contrast with the rich green of the other leaves. I also like the combination of California Hazelnut, Deer Fern, Redwood Sorrel and Wild Ginger.

Some of the most dramatic containers utilize the concept of combining a thriller, some fillers and spiller or two. Not all my containers will use this formula but I seem to be drawn to those that do. Plants in nature can be quite random in the way they grow together and still be lovely. Containers need a bit more order to dazzle and direct the eye.

Thrillers act as the centerpiece of a container. They are usually big, bold and beautiful. Giant Elk Clover is one such California native that is an attention getter. Chilopsis linearis-Desert Willow is another great subject for containers as it is slow growing and beautiful in leaf and flower. Other architectural natives that will catch your eye as the centerpiece of a container are Hibiscus or Rose Mallow and Pacific Dogwood. The thriller goes in the center of the pot or if your container will be viewed from only one side it goes in the back.

Next come the fillers. They can be foliage or flowering plants but they should complement and not overwhelm your largest plant. Usually they have a mounding shape and I’ll plant several around the thriller. Good fillers include Heuchera Maxima and Western Maidenhair Fern.

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California fuchsia

The last plants I’ll add are the spillers which are small and will soften the edge of the container. Redwood Sorrel, Wild Ginger and Miner’s Lettuce are good choices. California Fuchsia would look spectacular with its red or orange flowers and grey foliage spilling down the side of my container.

The best overall soil mix for natives in containers sharp sand and horticultural pumice added to a good potting soil. Never use perlite or that puffed up pumice because it will float and look terrible. Happy Container Gardening.

Gardening for the Birds with Cats

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My garden is alive with birds. Butterflies and bees also seem to find it an interesting place to visit. When I first moved up to this house in Bonny Doon the prior owners had hung a couple of small hummingbird feeders which attracted only a few hummers. Their plantings consisted of manzanita and ceanothus varieties. Both great plants to attract birds but not much diversity. It felt like I was living in a void without the sound of song birds or the whir of hummingbird wings. It’s taken me a season or two but between the new plants I’ve added and the seed, suet and nectar feeders I’ve hung throughout the garden I attract dozens and dozens of my winged friends.

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Sam Spade with his Birdsbsafe collar

How is this all possible sharing the garden with two cats? I knew right away that I couldn’t live with myself if I attracted birds only to have them endangered by Sam and Archer. As natural predators they couldn’t help getting into trouble. The problem was solved by the brightly colored, clown-like collar from Birdsbesafe they each wear that makes them more visible to birds. Neither wore a collar previously but they don’t seem to mind or notice they look like court jesters.

The birds in the garden are safe now or very nearly so and I’m happy too. It’s the height of breeding season and the birds are going nuts in the garden. I’m always on the look out for plants that will attract even more of these exquisite creatures. Fortunately there are many that have low water requirements which is a prerequisite these days.

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Purple finch

Trees that provide fruit, seeds, nectar and protein from insects attract many kinds of songbirds. Our native Big Leaf Maple is a favorite of the Evening Grosbeak who relish the seeds and early spring buds. Another bird magnet is the dogwood. Our Pacific dogwood as well as the Eastern dogwood and the hybrid of the two- Eddie’s White Wonder- are all very valuable sources of food for many birds. Their summer berries of dogwood are high in fat and important for migratory and wintering birds.

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Lesser goldfinch

In every garden possible I try to include low water use shrubs and perennials that attract birds. My favorite Lesser Goldfinch is partial to the seeds of yarrow, buckwheat and aster. Kevin’s mahonia is favored by Western bluebirds. Blooming now in our own neck of the woods is Mexican elderberry. Their butter yellow flowers will form purple berries rich in carbohydrates and protein and attract an incredible number of birds.

Both hummingbirds and butterflies are attracted to flowers that provide nectar. Among their favorites that won’t break your water budget are natives such as penstemon and salvia. I always can find space for another variety of salvia.
Galvezia, mimulus, monardella, California fuchsia and ribes are also important nectar sources for birds in your garden. Add a couple non-native, drought tolerant perennials like lavender, gaura, coreopsis, verbena, scabiosa, lantana and wallflower and you’ll provide a feast for all your winged visitors.

Everybody loves winged creatures in the garden. Adding plants that attract birds, bees and butterflies is at the top of the list of requests for nearly every garden that I design.

How to Save Water & Have a Beautiful Garden

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There was enough rainfall over the winter season for the California State Water Resources Control Board to modify their Emergency Water Conservation Regulations. On May 18th, 2016 it was adopted to recognize persistent yet less severe drought conditions throughout California and require local agencies to develop and implement conservation standards based on their particular circumstances.

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My friend, Adelyn, helping to water container plants and edibles.

The new standard requires local water agencies to ensure a three-year supply of water assuming three more dry years in the future like the ones we experienced from 2012 to 2015. Water agencies that would face shortages under three additional dry years are required to meet a conservation standard equal to the amount of the shortage.

Makes sense to us who have long been on the band wagon to conserve water both indoors and out. Our local water districts have both kept their water conserving restrictions in place. Since up to 70% of summer water use comes from landscape irrigation it’s a good place to start.

Both San Lorenzo Valley Water District http://www.slvwd.com – and Scotts Valley Water Districts http://www.svwd.orgoffer many tips and incentives to conserve water. Using less water-intensive plants, there are lists on their websites of drought-tolerant plants and water smart grasses, as well as replacing lawns with drought tolerant or native plants and/or permeable landscape materials such as mulch, decomposed granite, permeable pavers are just some of the ways you can keep your yard looking beautiful and also be water efficient.

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Rainbird Smart Irrigation controller

Rebate programs from local water districts offer several landscaping credits including sprinkler to drip irrigation conversion credit, weather-based irrigation controller credit, replacement credit for converting an existing lawn to water-wise grasses, greywater laundry-to-landscape irrigation conversion, rainwater catchment and downspout diversion. Both districts have guidelines and procedures to apply for the rebates on their websites.

Additional rebates from the California State Department of Water Resources are available to single-family residences for lawn replacement. This rebate application is separate from the local water District’s and you need to go online and follow the state’s guidelines in order to be eligible for these additional funds. See www.SaveOurWaterRebates.com for the details.

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Plants with similar water needs = hydrozoning

The fun part begins when you redesign the area where you took out the lawn or modify the plantings in other beds to include same water use plants. It doesn’t make much sense if you have some plants that require more water than the others in the same bed. You have to water to the highest water use plant to keep everybody happy.

Hydrozoning is the practice of clustering together plants with similar water requirements to conserve water. A planting design where plants are grouped by water needs improves efficiency and plant health by avoiding overwatering or underwatering. As you move farther away from the water source your plantings should require less water.

Now is the time before it gets hot to look at your irrigation system, plant choices and rebate options to save water and money and recharge our aquifers.

Kurapia – The Perfect Groundcover

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A groundcover is defined as any plant that grows over an area of ground. They are usually low-growing, spreading plants that help stop weeds from growing and prevent moisture loss. We gardener know that they do so much more in the landscape. Living ground covers add beauty to the garden filling in between plants while holding the soil in place and preventing erosion. They contribute to soil health by encouraging microorganisms. A garden wouldn’t thrive as well without ground covers.

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Kurapia groundcover growing in part shade

With this in mind I encourage many kinds of ground covers in my landscape. It’s a difficult place to find the best ones because of the lack of winter sun and only 5 hours of good summer sun. Still I’ve found a choice one that I’d like to share. It’s tough and reliable in many situations including hot summer gardens. If it will grow in my yard it will surely grow in yours.

Kurapia is ta deep rooted, low water use, low maintenance ground cover. It’s parent is in the Lippia genus and has naturalized worldwide. However, Kurapia has been bred to have sterile seeds and its growth habit is much more compact and tamed. Though it is sterile with respect to seed production, it does flower and is bee and butterfly friendly, blooming from May to October. This is a good groundcover if pollination of nearby fruit trees is needed or your want to encourage bees in your garden for general pollination. If bees are an issue for someone in your family Kurapia can be mowed once or twice a month to cut the blooms off. Mowing benefits this groundcover making it grow denser which naturally surpasses weeds once it fills in.

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Closeup of Kurapia flowers

Kurapia has been extensively studied at UC Davis and UC Riverside comparing it with No Mow as well as other drought tolerant cool and warm season grasses. Kurapia exceeded them all going 52 days without water and still maintained its green color. An extensive root system that goes as deep as four feet and a dense 2” to 3” tall mat-like top is the secret. The California sod grower recommends more frequent irrigation but it still requires just 60% of the water of a traditional lawn.

Kurapia does not require much fertilization either. One time in the spring for growth and flowering and once in the fall to keep the green color through the winter is sufficient. Mine looks great year round and I have to confess I’ve never fertilized it. Kurapia is evergreen and does not have a dormant period though growth stops or slows does in the winter. It spreads and self repairs by stolons. This groundcover grows in sun to partial shade requiring only three hours of sunlight. However it tends to stay more compact in full sun.

Kurapia will handle light to moderate foot traffic. It cannot take consistent high traffic though it is very walkable. My dog Sherman finds it great for his morning constitutional and I’ve never seen yellow spots as a traditional lawn will get.

Kurapia is hardy to 20 degrees though in tests it has survived temperatures as low as 12 degrees. It’s deep root system is unparalleled for erosion on slopes. Did I mention it takes 60% less water and how much you mow is up to you? Like I said, if it will grow in my garden under less than ideal conditions it will grow in yours.

What’s Old is New Again in Garden Plants

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Pittosporum tobira fragrant flowers

I remember walking with the main horticulturalist at Filoli Garden many years ago and hearing her extol the virtues of the established plantings that have survived drought and neglect with no pest problems for a very long time and are still growing beautifully in the garden. It’s not always the latest cultivars that have staying power. Some of the newer varieties are better but some are not as vigorous, some of those lovely variegated, striped or dark foliage plants revert over the years, some are prone to pests and diseases. Don’t overlook using been-around-for-ages workhorse plants in your garden.

Some of the survivors at Filoli Gardens over the years are California natives and others are just tough plants from other parts of the world. Take the common pittosporum you see in most every old garden. This plant makes a fine hedge, focal point or ground cover depending on the genus with a sweet fragrance in the spring while providing the bones or structure to your garden.

All of the various types of pittosporum are hardy in winter, grow in sun or shade and have low water needs. Pittosporum tobira flowers are scented like orange blossoms. Pittosporum eugenoides and tenuifolium – commonly grown as a hedge or small tree – have highly fragrant blossoms as does the ground cover ‘Wheeler’s Dwarf’.

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Lithodora ‘Grace Ward’

On a recent trip to the Gig Harbor, Washington area, lithodora ‘Grace Ward’ caught my attention in many gardens. With those electric blue flowers covering this ground cover it’s quite the show stopper. Lithodora is used more extensively than creeping rosemary in the Pacific Northwest as it can survive temps down to 0 degree or less. Growing with only moderate to occasional irrigation give this plant a try in your own garden.

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Agapanthus africanus

Next plant on my bring-back-the-old-favorites list is the lowly agapanthus or Lily of the Nile.  Sure you see it at every fast food restaurant and hotel you pass but the reason is that it grows and blooms so reliably with little care. This is one plant where the new cultivars are proving to be just a tough as the standard agapanthus africanus.

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Agapanthus ‘Storm Cloud’

Agapanthus ‘Storm Cloud’ produces luxurious green foliage that tinges purple-red in the winter months. In summer large umbels of very deep blue flowers rise above the foliage on tall blackish stems. This variety takes a couple years to establish but blooms reliably from then on.

Two smaller types of agapanthus are ‘Queen Anne’, a semi-dwarf variety and the dwarf ’Peter Pan’. Both are available with blue or white flowers. There is also a variegated dwarf called ‘Tinkerbell’ which grows well also. All agapanthus tolerate frost and neglect and require only moderate watering.

So in addition to all the ceanothus- a California native- that grow so reliably don’t overlook some of these other workhorses. There’s a reason these plants have been grown successfully for such a long time. Be sure you include these old favorites in your garden along with those new cultivars that you just have to try out.

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