1. Could you please clarify pruning. I have been reading about when and how re different hydrangeas. Does pruning mean cut the whole thing down eg in spring? Or just cut it back to the size you want it? I know some you need to do later in season.
2. Are there any bushes, flowers or non-invasive ground covers that will grow under fir trees?
Q1. As you have probably been reading, different types of hydrangeas require pruning at different times of the year. Pruning can range from trimming a few inches from the tip- back to a healthy bud, to pruning the entire shrub to within 12-18 inches from the ground.
Pruning can be a vague term when it is not used in context-relating to a specific plant, and literally means to round off a plant by cutting back stems or branches. Pruning has evolved since the old French word became popular in the sixteenth century. Some people still enjoy rounding off their shrubs and hedges, to control plant size or to create specific shapes.
Pruning is also important for plant health. Dead and broken branches should be removed when ever you prune. With Hydrangeas, this sometimes means sacrificing stems with flower buds to maintain the overall health of the shrub.
Pruning can also give you some control over the number and size of blooms to expect the following year. The key to knowing how much to cut off lies in identifying the plant you wish to prune.
In the case of hydrangeas, if you know you have an oakleaf hydrangea, Hydrangea quercifolia, for example, you will be aiming to tip prune your shrub just after it has finished flowering in late summer. If you leave it until the fall, you may notice that your shrub has already begun to develop new buds. Pruning too late can remove next years flower buds, resulting in an extra years wait to enjoy summer blooms.
If your hydrangeas have grown much larger than you anticipated, you can prune then back by a third, or up to a half, their size but they may take a year or two to flower again. It best to buy hydrangeas that grow to a size that fits your garden. There are many great dwarf varieties available now, which require infrequent minimal pruning.
I have added a link below to help you to prune your hydrangeas according to the types you grow.
Q2. Growing under any conifers can be challenging. As the needles fall to the ground and decompose, the soil pH is altered and over time becomes acidic. If your fir tree is mature it is likely to cast a fairly large shadow. Large trees are also efficient at absorbing what they need from the soil, competing with other smaller plants for water and nutrients.
These conditions created by most conifers give us the key to finding suitable plants to grow under or near them. Look for acid soil loving plants that have low water requirements and prefer part or full shade. Woodland natives are a good place to start.
Some attractive examples include: Ivory sedge (Carex eburnea); Pennsylvania sedge (Carex pensylvanica)
Ferns: Maidenhair fern (Adiantum pedatum); Lady fern (Athyrium filix-femina); Oak fern (Gymnocarpium dryopteris); Christmas fern (Polystichum acrostichoides)
Low perennials & ground covers: Woodland anemone (Anemone canadensis); Bearberry (Arctostaphylos uva-ursi); Mayapple (Podophyllum peltatum); Wild geranium (Geranium maculatum)
Shrubs: Wintergreen (Gaultheria procumbens); Hydrangea species- if you have enough dappled light and moisture
For more on growing hydrangeas, see: