Conifers are turning brown: what to do?

Brown spots on thuja, cypress & Co. are a nightmare for hobby gardeners. Often one fears an illness, but other causes are also possible. So what to do when conifers suddenly turn brown?

improve site conditions

Brown needles on conifers often indicate a problem, such as a poorly chosen location. Although the plants need light, they do not tolerate direct sun, as this can lead to burns. Locations on busy roads are also unfavorable, because both exhaust fumes and road salt can cause brown discoloration. If conifers turn brown for these reasons, it is best to react as follows:

• provide shade in case of sun damage
• e.g. B. by other plants
• Planting under tall trees is not recommended
• partially shaded place for conifers optimal
• with few hours of sunshine in the morning
• replace the floor if necessary in the event of damage caused by road salt
• Strengthen plants through nutrient supply

Check soil conditions

It becomes problematic when the conifer is in cold, wet and compacted or too acidic soil. A brown discoloration of the needles and shoots is then unavoidable. In addition, compacted and lean soils can cause a nutrient deficiency. This is how you can remedy the situation:

• replace loamy, hardened soil
• Loosen the subsoil regularly
• mix some sand into the ground
• Be sure to test soil that you think is too acidic
• PH value increase by adding lime
• apply fresh compost after three months
• lean soils with mature compost, stable manure or horn shavings improve

Tip: If a nutrient deficiency caused by poor soil conditions is serious, you can administer a special conifer fertilizer after the adjustment.

compensate for lack of water

Too little water can also cause your conifers to turn brown. This can be due, for example, to insufficient rainfall, high temperatures, intense solar radiation, too windy a location or competition from other plants. How to fix?

• Significantly increase watering
• only water in the evening or in the morning
• directly on root disk
• if necessary, dig a ditch around conifers
• fill with water until bale is soaked
• water more frequently during dry periods
• thick layer of mulch protects against moisture loss

Waterlogging can also become a problem. It can lead to the conifers no longer being able to absorb water. The result is root rot. To prevent this, young specimens in particular should be watered regularly during dry periods and on frost-free days in winter. This is important because these trees lose a lot of moisture through their needles.

fix nutrient deficiencies

In order for the plants to remain juicy green and healthy, they need a regular supply of nutrients. If, on the other hand, the conifers turn brown, there is often a magnesium deficiency, favored by too dense planting, poor soil conditions, road salt or unsuitable fertilizers. To replenish affected plants, you can do the following:

• quick remedy Epsom salt (magnesium sulfate)
• prepare the appropriate spray solution for this purpose
• from 200 mg Epsom salt and 10 liters of water 
• Spray the solution on the needles
• only in cloudy weather
• repeat after ten days
• If necessary, also work into the soil
• then water well

You can repeat the spraying with an Epsom salt solution several times at intervals of 2-3 days. Apply Epsom salt directly to the ground, calculate with about 100 g per meter of growth. Also preventive is an annual Fertilization with Epsom salt recommended.

Tip: Ideally, before using Epsom salts, you should have a soil analysis done to make sure you are actually magnesium deficient.

get rid of pests

Among the pests, the leaf miner in particular can be dangerous to conifers. At first only the tips of the shoots are affected, later whole branches of the conifers turn brown. If an infestation is detected, you should act as soon as possible:

• remove all affected shoot tips
• then dispose of in household waste
• not on the compost
• Then spray the conifers with a hard jet of water
• in the case of advanced infestation, use of pesticides
• Application period June to July

Tip: If you look closely, you can see drilling and drilling holes on the tips of the shoots as well as small approx. three millimeter caterpillars or pupae.

combat fungal infestation

In conifers, various fungal infections can be responsible for browning, such as Pestalotia dieback, scale and needle blight, and Kabatina branch dieback. When Pestalotia shoots die back, the tips of the shoots turn brown, with the color reaching into the interior of the leaf. The dandruff and needle tan affects older plants. Shoots turn brown in the lower area. And with Kabatina branch dieback, younger shoot tips are affected. Fast action is required now:

• Cut off affected shoots generously
• don't cut into old wood
• Too acidic soil and lack of nutrients favor fungal infestation
• therefore test the soil and lime if necessary
• Avoid magnesium deficiency
• Disinfect cutting tools before and after cutting
• treat preventively with fungicides

Tip: If the infestation is severe, all you can do is dig up the plant and dispose of it.

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