Citrus in the Rockies

Shepherdess Celeste grows a whole citrus orchard in the Rocky Mountains!  Yes, it's true!  Lemons, limes, and oranges.  I have not tried grapefruit yet.  Right now we have a blizzard, sometimes it is -50 degrees Fahrenheit but my citrus trees don't care.  They are loving it! 

My citrus trees stay inside until May and come back inside when the killer frost is imminent.

Citrus trees bring allot of joy to ones life, the fragrant blossoms, the green foliage, the tempting fruits.  How many people do you know that are picking their own Mandarin Oranges off their trees in December?

That said, they do need care on occasion but overall they are not a fussy plant.

Everyone including your citrus and plants love TLC! Babying your citrus trees:

Any house plant loves to have their leaves polished with a damp cloth to get off the dust. In that way they can breathe easy. if you let the dust build up is like asthma to a plant.

This is a nail citrus (one) has dull pale leaves and so I need to treat it, fertilizer of magnesium or iron. Not really sure which. They are heavy magnesium feeders so I will being with that. Epsom salts to the rescue!.

Yellowing leaves

Citrus are gluttons for food. When nutrients are in short supply, their leaves turn yellow and they crop poorly. Feeding with a complete citrus fertiliser will fix most of the problems – or help you to avoid them in the first place – as they provide the nutrients that your citrus trees need. But if you're experiencing problems, take a closer look at the leaves.

With a magnesium deficiency, for example, mature leaves turn yellow, with an inverted green V shape at the base of the leaf, and green on the tips. It's often seen on acidic soils. Applying Epsom salts will correct the deficiency. Dissolve 2 tablespoons in 10 litres of water and water into damp soil.

An iron deficiency occurs on young leaves. Light yellow/white leaves and green veins are the signs. It's common on alkaline soil. Treat with iron chelates applied to the soil.

A zinc deficiency occurs on new growth and remains on the leaves as they mature. It results in small, narrow leaves, yellow mottling and twig die-back. It's most prevalent on alkaline soil. Dissolve 2 tablespoons of zinc sulphate in 10 litres of water, with a wetting agent, and spray foliage in spring.

Manganese deficiency shows a dark midrib, dark green veins and light green interveinal areas, which give a mottled appearance. Use a foliar spray of manganese sulphate.

An overall yellowing of leaves indicates a nitrogen deficiency. It occurs on older leaves first. Leaves may eventually drop. Feeding with a citrus fertiliser should fix the problem.

Lemon scab

Lemon scab, or verrucosis, is a common sight on lemons. Tiny lumps, or wart-like protrusions, appear on the skin of the fruit and leaves. It does not affect the inside of the fruit, and many people just leave it alone. In severe cases it may reduce the vigour of your trees. To control it, regular spraying of copper is necessary. Remove infected fruit, leaves and twigs and spray before, during and after flowering.

Fruit drop

Fruit drop is a common occurrence among citrus trees. A part of that is normal – it happens when a tree sets more fruit than it can support (often youngtrees). First, blossoms drop without setting fruit, then pea-size fruit falls from the tree, then fruit the size of golf balls may fall off. This can all be normal.

Continuous fruit drop, however, is not. This can be brought on by many factors, though typically it's a result of environmental stress (cold wind, sudden changes in temperature, inadequate nutrition, lack of moisture, etc) or poor pollination.

Adequate moisture during the early stages of fruit development is crucial. If rain is scarce, regular watering should is necessary. Apply a layer of mulch to conserve moisture in the soil, though keep the mulch away from the trunk or it may rot. Clear away any weeds too as these compete for water and nutrients. In cooler areas, keep your plants sheltered from cold winds. If moving them into a protected spot over winter, do so gradually to give the plant time to adjust.

Leaf drop

Citrus trees naturally shed leaves from time to time. The leaves have a life span of around 3-4 years, so they will simply drop off after that. That's natural. But if a lot drop off all at once, or over a period of time, then something's not right. Leaves will drop after a sharp drop in temperature, when frosts hit, if plants are water stressed (not enough or too much), or if they're given too much food. Plants that are root-bound may also drop their leaves.

Sooty Mold

Sooty mould is common on citrus. It's a black fungus that grows and feeds on the sugary wastes (honeydew) excreted by sucking insects such as whiteflies, scale insects and aphids. Ants are often present too, but they are not the cause of the mould – they feed on the sugary honeydew. In small amounts it does not overly harm plants, but a large covering of the mould blocks light from the leaf surface and reduces photosynthesis. You can simply wash off the mould with soap and water, but you also need to deal to the pests as well to stop the mould reoccurring.