The following advice applies in general to growing herbaceous perennials in your garden.
For specific advice for individual varieties, please see the relevant variety description page.
When to Plant
Spring plantings are common as it gives plants a good opportunity to establish before the summer. Spring is also a good time to divide many perennials.
Summer plantings can be successful, as long as sufficient water is supplied.
Autumn planting is often a good idea for varieties that bloom in early spring. Plant at least one month before frost is expected to allow plants to establish before going dormant.
Consider the sun and shade conditions in your garden and choose plants to match.
Sun = direct sunlight for six hours or more per day
Part Shade = less than six hours of sunlight per day
Shade = no direct sunlight
Choose healthy, vigorous plants. Avoid those with dry, pale, shriveled leaves or any with signs of insects or diseases.
Don't worry if plants are not in flower. Perennials are generally sold before their normal flowering period and will flower later if they have been properly conditioned.
Planting Site Preparation
Improve both dry, sandy soils and wet, clayish soils by incorporating 10-15 cm of organic matter into the planting site to a total depth of 20-30 cm.
Organic matter includes various composts, aged (not fresh) manure and peat moss.
Soggy areas will need either drainage tile or a 20-30 cm raised bed.
New planting sites should have a soil test after incorporating organic matter to determine pH (desired pH range of 5.5 to 6.5) and nutrient content.
In general, new plants will benefit from incorporating 2 pounds of either superphosphate or bone meal along with 2 pounds of a granular fertilizer (5-10-5, 5-10-10, 10-10-10) into the top 6 inches over a 100 square-foot area.
How to Plant
Dig a hole about the same depth and double the width of the plant's root ball.
Remove the plant from the pot. Loosen the roots by making three to four shallow cuts with a knife or trowel to the sides and bottom of the root ball.
Place plant in hole, with top of root ball level with the surrounding soil and fill halfway with soil. Fill hole with water and allow to drain.
Fill the remainder of the hole with soil and water thoroughly. If desired, apply 5-5 cm of mulch around plants for weed control and to aid moisture retention.
Caring for Your Plants
Water is critical for establishment; apply 2.5 cm of water (rain or hose) per week.
Be sure to control weeds around plants until they are established. Mulching helps but some hand weeding may be needed.
If sites are prepared properly, little fertilization is needed. But it can be helpful in early spring as new growth begins. Use less fertiliser for ferns than other plants.
Refer to plant care labels for specific cultural practices for your perennials such as pruning, division, etc.
Stake taller plants or support in a wire cage to reduce wind and rain damage.