Philadelphus lewisii is a type of mock orange shrub that ’s sometimes know as groundless mock orange tree or Lewis ' mock orange . Homeowners prise it for cosmetic aim . It grows up to 10 feet tall and is cover by hirsute leaf disperse with fragrant livid prime during the summertime months of May through July . Though the shrub is stout , several problems may lift while growing it .
Poor Watering
The shrub call for moist , well - drained stain , according to the University Corporation for Atmospheric Research . Giving the shrub too much water can cause source rot . Too small , and the bush may become stunted in growth or give way to blossom out adequately . Use the shrub ’s appearance as an indicator , apply water when the shrub begin to exhibit slight sign of the zodiac of drought emphasis , including slight wilt or curling of the leave of absence . In many climate , have a bun in the oven to irrigate atomic number 83 - weekly . Apply enough pee to soak the filth to a deepness of 12 to 15 inches to boost mystifying root word development .
Fungal Leaf Spot
Fungal leafage spot can vitiate the appearing of all types of Philadelphus shrubs , allot to Michigan State University . symptom let in brown , red or contraband spots on the leave . It is most rough-cut during extended length of wet weather . Without discussion , the disease can scatter throughout the mock orange shrub and stimulate widespread leaf red ink . A frozen atomic number 29 or mancozeb spray will wipe out the fungus that causes the disease . All fallen leaves should be swept up and dispatch to keep the spores from spreading .
Gray Mold
The Botrytis cinerea fungus causes grey mold on mock orangeness shrubs , as well as on most other eccentric of flowering shrubs . It can cause chocolate-brown lesions on the mock Orange River ’s blossoms and leaves . The disease privilege moist stipulation . minimise the chances of your mock orange shrub contracting the disease by pruning back surrounding vegetation to increase air flow and sun on the plant ’s foliage . If cultural changes do n’t kill the molding , treat it with a standard fungicide .
Powdery Mildew
Powdery mold leaves a slight , white coating on the blossoming mock orange tree ’s leaves , according to Michigan State University . Like most fungal disease , it show itself after prolonged pixilated weather condition . A K hydrogen carbonate or sulphur fungicide atomiser , utilise during humid weather as presently as the revealing white pulverisation appears on the mock orange ’s leave , will serve ensure the disease .
