Category Archives: fertilizing

Fruit Tree Care – Fertilization & Summer Pruning

Whether you grow one fruit tree or a home orchard full of them there is always something to learn from an expert and Orin Martin of UCSC Farm and the Alan Chadwick Garden is just the guy to help. With nearly 40 years of hands-on experience at UCSC he says he?s come up with a successful method of caring for fruit trees including pruning and fertilizing . ?I?ve made every mistake in the book?, he laughs.

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Orin Martin explaining summer pruning

The UCSC Farm and Alan Chadwick Garden on the campus are both internationally known for training, research and public education. Recently I had the opportunity to join Orin during the Summer Orchard Walk at The Farm as he discussed the care of fruit trees and summer pruning to improve tree shape and productivity. Between jokes he shared many tips including the importance of fertilization and preparing an orchard for fall and winter.

Deciduous fruit trees are genetically programmed to start root growth early as they originated in the cold winter climates of Northern Iran, Uzbekistan and other central Asian areas. Their growing season begins in January or February which is 3-5 weeks prior to any visible bud swell when soil temperatures are still in the low 40?s. With this in mind Orin recommends starting fertilization early. Organic fertilizers take longer to become available to the tree and you want to maximize the early growth spurt in spring.

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Sunflowers attract pollinators to garden

Orin has a recipe for fertilizing young fruit trees that is used throughout the Farm and Garden. It?s comprised of compost and an organic source of nitrogen such as blood meal, 8% Nitrogen Sustane or Dr. Earth granular. A young tree will need additional nutrients in May and possibly July if the tree is not putting out sufficient structural growth. Fast acting liquid fertilizer such as fish emulsion and liquid kelp can be substituted for the early summer feeding. The second wave of growth occurs in fall. Slow acting organic fertilizer is best at this time.

Next year?s fruit buds are formed in late spring to early summer at the same time current fruit is growing so nutrient needs are extremely important at this time. If a mature tree is growing well its yearly fertility needs may be met by growing a bell bean crop as green manure over the winter.

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Ginger Gold apples with resident cats

The two resident garden cats followed our group as Orin demonstrated summer pruning of Ginger Gold apples, Flavor King pluot and Seckel pears. Most are trained to a open center with some having a modified central leader. I asked what he would do if no central leader grew after heading back a young tree whip. ?Then I?d train it with an open center. You?ve got to play the hand your dealt?, he laughed.

?Ladderless? harvesting and care is the goal to pruning in summer and winter. Summer pruning from early August to mid September stops growth and is done to limit height and length of branches to encourage more fruiting shoots. Winter pruning creates the tree?s structure. ?When you don?t want a tree any taller, stop winter pruning?, Orin told us.

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UCSC Farm crops

Throughout the orchard walk Orin Martin shared interesting tidbits of information. Seems that pest problems such as European blister mite and pear slugs are being observed here at for the very first time.

The USCS Farm & Garden has free monthly guided tours as well as a calendar of educational talks and events. It is open daily for everyone to learn and enjoy. Kids tours are offered during the school year in the Life Lab Garden Classroom.

Troubleshooting Plant Problems

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.

April: For Everything there is a Season

crabapple_Pink_ProfusionSeems like just about everything is in bloom. Sure there are many plants and trees who?s season is still a ways off but the flowers of early spring really get our attention. Longer days trigger both flora and fauna to reproduce. Being that it?s the beginning of April I thought I?d give you a heads up on what to do in the garden this month. That way you can budget your time and enjoy the beauty around you and still get your chores done.

Earth Day is coming up on Saturday, April 18th and National Arbor day is April 24th. What better way to celebrate in your own backyard than to planrhodie_early_pinkt a tree, shrub, flower or edible? I?m enjoying the succession of flowering trees in my own yard. First came the plums, then the flowering crabapple and now the Forest Pansy Redbud. My crape myrtle will bloom by summer but I think I?ll plant another tree that will bloom in May to celebrate, maybe a late-blooming Kousa dogwood.

Planting a tree is having confidence in the future. Like the saying goes, ?The best time to plant a tree is twenty years ago. The second best time is now.? In case you were wondering, Arbor Week in California was celebrated mid-March. That?s because each state observes Arbor Day based on the best tree-planting time in their area. On the first Arbor Day, April 10,1872, an estimated one million trees were planted. Make yours the one million and one tree planted.

Other to-do?s for this month include:

Fertilize -Take advantage of the moist soil to fertilize your garden. Lawns and groundcovers are beginning their spring growth spurt and new leaves on trees, shrubs and perennials are starting to emerge. Your citrus may be looking yellow from lack of nitrogen which has leached out of the soil through the winter season and they may be lacking in iron. Feed them with organic citrus or fruit tree fertilizer. Perennials benefit from both a fresh layer of compost and a light application of balanced fertilizer. They respond to the phosphorus from bone meal especially in the spring for root growth, stem sturdiness and flower development. Make sure you keep fertilizer off the foliage and crown of the plants or wash it off with the hose. Wait to feed azaleas, camellias and rhododendrons until after they bloom and you see new leaves emerging.

Transplant – If you need to move any plants in the garden that have outgrown their space or are not growing with other plants of the same water usage now is a good time. Plants are full of growth hormones and recover quickly from transplant shock. As you plant new additions to the garden add organic matter to the soil. If your garden’s soil is sandy, organic matter enriches it and allows it to hold water more efficiently. If your soil tends toward clay, organic matter will loosen it up and improve drainage. In well-amended soil, plants grow deep roots, are hardier for cold, more resistant to disease and more drought tolerant. Organic matter such as compost, planting mix and well-rotted manure boosts nutrition and improves soil structure.

Spread fresh compost or bark mulch around all your plants to help plants get off to a strong start. Good soil is the secret to successful gardening. The first principle of organic gardening is to feed the soil and it will feed the plant. Remember that all gardening used to be organic. Layer 2-3″ of compost or bark chips on top of the soil and let it slowly decompose and filter down into the earth. Bark nuggets and shredded bark do not increase your soil’s fertility like compost or bark chips but they do conserve moisture and help keep weeds at bay.

Check for aphids – They are out in full force sucking plant juices from the tender new leaves of everything from roses to hellebore to Japanese maples. A strong spray from the hose may be enough to dislodge them. If they still persist, you can spray organic insecticidal soap, neem oil or horticultural oil to kill them. As with all pesticide sprays, do this early in the morning or later when they are not in the sun. Be sure to test first to make sure the spray doesn’t burn the new growth and always mix according to the directions.

Ants can also bring aphids up into trees and shrubs such as camellias, citrus and roses. Ants feed off honeydew secreted by aphids, scale and other plant-juice sucking insects. Ants also protect these pests from natural predators. To keep them off, wrap trunks with a 1-2″ wide strip of masking tape and coat with a sticky barrier like Tanglefoot. Keep the barriers free of dirt and check them periodically for breaks. Reapply when necessary.

The most important to-do for early spring is to take time out and enjoy your garden and our beautiful surroundings. Those last few weeds will be there tomorrow but you’ll never get another today.