The anticipation of a self-grown blue spruce as a Christmas tree experiences a severe setback when the wonderful tree becomes ill. Read here which diseases can attack a spruce. Benefit from our tips for effective prevention.
Fungal diseases are the most common ailments of a blue spruce
Fungal pathogens cause needle drop
There are different types of fungi that can affect your blue spruce. Although the course of the disease differs, the dilemma always ends in the shedding of the beautiful needle dress with the blue shimmer. In the following we have compiled the most important fungal diseases for you with information on the first symptoms:
- Spruce needle rust (Chrysomyxa spp.): Yellow spores on needles in summer; mostly near rhododendrons
- Spruce needle scab (Lirula macrospora): The needles turn light yellow with elongated, black spores
- Spruce needle blush (Tiarosporella parca): Black nodules form under the epidermis, making the needles appear reddish
Despite slight differences in visual appearance, the needles eventually turn brown and fall off. In contrast, numerous other fungal pathogens have adapted excellently to the parasitic way of life and do not cause any damage that could endanger their existence.
This is an effective way to prevent fungal diseases
Don't wait for the needles on your blue spruce to change color and fall off. So far there has been a lack of effective means of combating diseases that are approved for home gardens. With the following precautions, you can deprive cunning fungal spores of their livelihood in advance:
- Consistently mulch the tree disc flat with leaves, grass clippings or bark mulch
- Regularly shower the mulch layer with nettle manure
- Do not administer a nitrogen-rich complete fertilizer, but fertilize organically with leaf compost and rock flour
The key to keeping a blue spruce healthy is a pH value between 6.5 and 7.5. It makes sense to check this value every few years using a test set from the hardware store or garden center. An increase in the alkaline range greater than 8 is alarming. In this case, the administration of Epsom salt causes the pH value to drop within a short period of time.
tips
Are you looking for a short, hardy blue spruce for pot cultivation? Then you will find what you are looking for in the 'Fat Mac' variety. After 5 years, the dwarf tree has only reached a height of 20 cm. In addition, this American hybrid has proven to be exceptionally resistant to most diseases.