Answer: These hydrangeas grow well in a location with direct morning sun or bright dappled light all day long. Avoid hot afternoon sun.
Select a spot with protection from winter winds; this is very important in preventing excessive winter damage to the stems.
They will do best in organic, humusy soil that is evenly moist yet well drained. In a native clay soil, you might try a slightly raised bed or plant on a slight slope to improve the drainage. Also amend the soil in the planting bed generously with organic matter such as compost, shredded and rotted leaves, well aged stable manure/bedding, and/or milled spagnum peat moss along with a small amount of coarse sand.
When you plant, loosen any encircling roots and dig a hole that is three or four times wider than the root ball. Set the plant at the same depth as it grew originally, no deeper. Firm the soil around the roots and water generously to settle any air pockets.
Using an organic mulch year round will also help feed the soil on a gradual basis. During the summer it should be about three inches thick in a flat layer over the roots, in late fall add more for winter protection. The mulch also helps keep the soil moister.
During dry spells, and especially while they are becoming rooted and re-established, you will need to water. To know if you should water, dig into the soil with your finger. If it is still damp, do not water yet. When you do water, apply it slowly and thoroughly so it soaks deep down into the soil. After watering, wait about twelve hours (on clay) and dig down to see how far it actually went; sometimes it can be surprising. With clay soil, it is especially important to water slowly, such as with drip irrigation, so it can be absorbed into the soil.
Do not fertilize now, it is too late in the season for that. Fertilizing now could encourage late season growth that would not have time to harden before winter. Wait and fertilize next spring. Correct watering is far more helpful to them. Good luck with your hydrangeas!
Q&A Library Searching Tips