Climbing Ivy’s OK to Use on Modern Bricks, Mortar
QUESTION: I would like to grow climbing ivy on the brick walls of my house, but I’ve heard that the plant could damage the wall. Is this true?
ANSWER: There is a widely held misconception that climbing ivy will damage any masonry wall. If stucco or the mortar between bricks or stonework is in poor condition, then an exuberant ivy plant will undoubtedly weaken the structure as its aerial roots attempt to extract moisture from the masonry.
The roots invade broken joints or cracks; when they find a source of nourishment for the main plant, they expand and burst the weak material, which accelerates deterioration by encouraging moisture penetration. If the ivy is allowed to grow unchecked, the weight of the plant can eventually topple a weakened wall.
But with modern hard bricks and mortar, ivy can do no more than climb by the aid of training wires and its own sucker-like roots. So long as the structure is sound and moisture-proof, there is some benefit from ivy clothing a wall in that its close-growing mat of leaves, mostly with their drip tips pointing downward, acts as insulation and a watershed against the elements. Where ivy is permitted to flourish as a climber, it must be hand-pruned to prevent it from penetrating between roofing joints and vents and clogging gutters and downspouts.
Vinegar May Offer Concrete Solution
Q: Dark brown spots are appearing in areas of my concrete deck. They don’t wash away with soap and water. What causes these spots?
A: The type of discoloration you describe occurs when tricalcium alumino-ferride--the agent that gives portland cement its gray color--has not reacted thoroughly with the other chemicals in concrete. To remove the dark spots, try pouring on undiluted household vinegar. If that doesn’t work, try a solution of 1 part muriatic acid to 30 parts water.
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