Q.Hi My Name Is Patricia Stokes And I Was Wondering How To Take Care Of Hydrangeas The Proper Way. Let\’s See, My Husband Tends To
s ee them them and says their fine, but I beg to differ.
Well, the picture is a too “off color” (too brown-ish) and grainy and I cannot identify some leaf problems as a result. The shrub does not have many blooms and has several leaves showing an unrecognizable color change away from dark green, possibly caused by several types of leaf spots or nutritional issues (rare in Washington state unless near the beaches): bacterial leaf spots are common starting at the end of Spring; cercospora leaf spots are common around mid-July through Fall; black leaf spots; and anthracnose leaf spots. Review the basics.
Sunlight - The type of hydrangea in the picture is either a hydrangea macrophylla or hydrangea serrata. They prefer dappled sun or morning sun only (until 10-11am, so no afternoon and no evening sun)
Fertilizing - Hydrangeas are not heavy feeders like roses are so maintain 2-4" of organic mulch at all times and plan to fertilizes until they become well established. If your soil is not deficient in nutrients then quit fertilizing and let them feed off the decomposing mulch and the nutrients in your soil. You can fertilize once in Spring after your average date of last frost using about a cup of organic compost, composted manure, cottonseed meal or you can also use a general purpose, slow release, chemical fertilizer with a NPK Ratio of around 10-10-10 per label directions. During the rest of the growing season, you can also use liquid seaweed, liquid fish or coffee grounds but stop all fertilizers when it is too hot or three months before your average date of first frost. Using too much fertilizer can keep the plant in grow mode in the Fall and early frosts can then injure or kill Spring flower buds. Fertilizing too early for your zone can also cause similar problems with late frosts.
Watering - to reduce the chances of fungal infections, avoid watering the leaves or blooms. Water the soil instead. To know when to water, insert a finger into the soil to a depth of 4" (the typical depth of most hydrangea roots) and water if the soil feels dry or almost dry. Do not water if the soil is already moist or soggy. This also minimizes the chances of getting root rot. To know if you watered enough, water as usual; wait for the water to drain; insert a finger into the soil in a few spots to a depth of 8". If the soil feels dry, the soil may not be draining well, you missed a spot when watering or the plant needs more water than you are providing. When temperatures typically exceed 85°F, increase the amount of water per watering of each hydrangea. When temperatures typically exceed 95°F, consider doing some hand watering too if the soil feels dry at a depth of 4". When temperatures recede and typically stay below 95°F, discontinue the optional hand watering but continue watering at elevated summer levels. When temperatures recede and typically stay below 85°F, resume watering at Spring watering levels. Once the plant goes dormant, consider watering once a week or once every two weeks depending on local rains. Discontinue watering if the soil freezes; otherwise consider watering if winter is dry (check the soil at a depth of 4"). Begin watering at Spring levels once you see leaf out or new stem growth. Keep weeds away from the hydrangeas as both have shallow, tiny root systems near the top of the soil.
Pruning - These two hydrangeas types can bloom either on old wood or on both old & new wood. Prune after the plant stops opening new blooms. Spring blooms will develop from flower buds in old stems; those flower buds typically develop at the end of the previous growing season and are located inside the ends of the stems until they open in Spring. If you do any Fall pruning after these stems have developed (but not opened) Spring flower buds, you would be cutting off the Spring blooms. Depending on your location, that could be any time from mid-July thru early Fall. Hydrangeas normally do not need to be pruned, except to remove any dead stems that do not leaf out by the end of May each year or if planted where a lot of snow falls on top of the plant during winter. Macrophyllas/serratas that bloom on new wood too are called rebloomers but they are actually remontant varieties: they will also bloom when the new Spring stems grow tall and old enough to develop flower buds and immediately bloom. Sunlight will help producing blooms. A remontant variety that is compact will also be able to reliably bloom in the summer from new wood. If your soil is sandy, I would suggest not stopping the fertilizer applications when the plants become established. Instead, follow the product directions. Organic fertilizers like cottonseed meal, organic compost or composted manure can be treated as if they were slow release fertilizers, which you usually re-apply every three months or thereabouts.
Lack of blooms: unless someone already pruned the blooms, general causes are: too much shade; nutrient issues (common in sandy soils); pruning the flower buds before they open; too much fertilizer; deer, squirrels and bunnies can eat the flower buds when they open; hydrangeas that only bloom on old wood can have the flower buds killed by very cold temperatures so protect them from late frost and consider using winter protection. Macrophyllas/serratas rarely have winter issues when they bloom on new wood but an extreme winter event can never be ruled out.
Leaf spots: avoid overhead watering as much as you can; water only when the soil feels dry at a depth of 4” instead of using a watering schedule (water every “x” days); maintain the soil as evenly moist as you can (not dry but not soggy); increase the amount of water when the plant gets too much sunlight, temperatures are above 85F; it is windy; low humidity. Follow clean sanitation practices. Hard to give you more information as the picture was not clear enough to be able to diagnose the dark and color of leaf sections.
