The cultural needs of plants are the particular growing requirements that each plant has. It's the longing for shade by certain columbines. It's the need for full sun by yarrow and yucca. It's rough soil for this plant and rich soil for that one.
Grouping plants by cultural needs is an aspect of gardening often overlooked or not considered because it's too easy to plant favorite shrubs and flowers together. But if you have a flowerbed that isn't doing so well, double check and make sure these favorite plants have the same growing needs. If you're making a new bed, this is the time to decide what kinds of plants you want—and to make that decision based on those plants' needs.
This certainly takes away the hit-and-miss style of gardening. Now you need to plan. For instance, the soil in a bed for xeric plants can be a little lean. Yet there needs to be drainage.
For a bed of annuals, the soil needs to be richer and needs to hold water a little more. Use Soil Mender Blend for creating a bed for xeric plants. Use Soil Mender Compost for the annual bed.
Some of the things to keep in mind for cultural need groupings are:
sunlight and shade
Some of the benefits of cultural grouping include reducing disease and root rot, plus saving you time and worry. It's hard to be sure when you're fertilizing a plant that needs rich food that it won't sneak into the roots of another plant that likes things a little poor.
Another sub-element in cultural needs is zones. Your garden may be zone 5 overall, but playing with microclimates is one way you can fudge a bit. The hot spots created by walls and the cooler areas created by taller plants can definitely be used to your advantage. If you have a hot wall, it's possible to push things up a zone. Working with zones often comes down to experimenting. But creating zone pockets still requires all the other elements of cultural needs for plants.
Planting your gardens based off of cultural needs is a good practice to consider.