Herbaceous Perennial Growing Tips

Perennial plants are the mainstay of the flower garden; many will flower all summer, becoming dormant in autumn to reappear in spring. Perennials tend to be non-fussy plants and are easy to look after - they just need the old stems cutting back in late autumn, which helps to promote new stems and vigorous growth the following spring, getting bigger and better every year!
Perennials include many garden favourites including Geraniums, Echinacea and Alchemilla and will add fantastic colours and textures to your beds and borders.

Planting Bare-root Perennials

We deliver many of our perennials as bare-rooted plants. There are a number of advantages for this;
• It’s an economical way of getting lots of year-after-year flowers for your border
• Main root structure is strong and well-developed
• They quickly establish to produce more roots once they’re in the soil

As long as the ground is not waterlogged or frozen, bare-root perennials can be planted straight away (or within the next few days). Keep plants cool and out of direct sunlight, until planted. It’s a good idea to give them a soak in a bucket of cold water for a couple of hours prior to planting, to make sure the roots are hydrated. Dig a hole that’s large enough to fit the entire root mass. Add a little general fertiliser to the planting hole to give the bare root plant a boost when planted. Spread the roots out in the hole to encourage them to penetrate the surrounding soil in all directions. They’ll establish and develop quicker. Space bare-root perennial plants roughly 12-15cm (5-6 in) apart in each direction. This spacing distance is a general rule of thumb. Some varieties spread more like perennial geraniums. These can be planted 20cm (8in) apart. Mark the planted area with a cane or plant label so that you know where they are. Give the planted area a good soak with water straight away after planting.

Until your perennial plants are established, water them daily in the morning or evening or both during very hot weather. However;
***Do not overwater young plug plants
If young seedlings or young plants have rotted, more or often than not it’s down to over-watering.
Prevent this from happening;
• When young, water from above when soil feels dry until roots are emerging from the bottom of the pot.
• Never stand pots in water for a length of time. Roots need to breathe and get sufficient oxygen; if you keep them standing in water they drown.

A good tip for established plants is to stand them in a tray of water overnight, if the soil is dry. In the morning tip out the excess water from the tray. Only ‘flood’ the tray again when soil surface feels dry to the finger tip. Again, make sure you re-visit after a few hours or overnight to tip out excess water.

Tall plants may require some support once they reach full height in the summer. They can be tied to canes or plant supports. For best results, provide a support for your tall plant to grow through whilst they’re still small as it tends to look more natural and prevents breakages to the stems.
Some perennials benefit from regular dead-heading during the summer. It keeps them looking fresh and encourages them to form more flowers. Look out for dead flowers on plants and snip them off as and when you see them. Once your perennial has stopped flowering in the autumn, use secateurs to cut the stems down to 2.5cm (1 in) above the soil surface, or cut back in early spring. Remember to mark where your plant is growing if you can’t see it afterwards. Providing it had a successful first season, it will grow back each year, bigger and stronger.
Tip- Planting each variety in odd numbers tends to give a more natural look. (For example, plant three perennial geraniums next to five echinaceas and three heleniums).

Planting Plugs

The advantages of getting in plugs over bare-root are;
• Easy to handle
• Ready to grow and flower as soon as they are in the ground
• Can keep longer as plugs, if watered, until ready to plant

Receiving your medium-sized plug plants when they arrive in spring.

Remove the cardboard packaging and water the plants on arrival. They can be safely left in the tray for a few days but do not allow plants to dry out. Keep out of direct sunlight to protect the young plants from scorch or drying out. Potting your medium-sized plugs plants up & then growing them on in the ground outdoors. Use a dibber or pencil to push the plants out through the base of the plant tray to avoid damaging the plant. Pot up into trays or individual pots - our Potting On Kit is perfect for the job. Pot each plug into 7.5cm (3in) pots using a good multi-purpose compost or a container compost. When potting up the plugs handle the plants carefully by the root ball (the plug-plant soil) to try and avoid damage to the stems. Fill the pots or trays with good compost with a little slow-release fertiliser mixed in. Grow on for a few weeks in a light, frost-free place, but try to avoid direct sunlight. Keep them moist but do not over-water. Some varieties naturally grow tall and leggy at first. They can be encouraged to ‘bush-out’ by pinching out the growing tip. You can do this literally by pinching off the top of the plant just above a branching point. When plants have grown and formed a good root system within their pots they can be planted straight outside. Most bedding plants need to be spaced at 30 40cm (12-16 in) apart, depending on their overall size. Check 'Variety Information' table below for plant spacing details.

Receiving your large-sized plug plants when they arrive in spring

Remove the plants from the packing straight away and sit them in a tray of shallow water, allowing the plugs to fully soak. Once the plugs have soaked, remove them from the tray of water, allow to drain and position them outside, out of direct sunlight. One of the best things about our large-sized plug plants is that it isn’t necessary to pot them up and grow them on before planting outside, if you are short of time. It isn't necessary but it is recommended we recommend that you do for best results.

Growing them straight after in the ground outdoors
If planting straight outside without potting on first, make sure they are in a sheltered or protected position. Sometimes plugs are vulnerable in exposed sites or where there are pests or pets. Before planting your large plugs, thoroughly dig and add some granular fertiliser to the soil first. Doing this provides an easier environment for the young plants to establish their roots. Dig an individual hole for each plug, deep and wide enough for the entire root ball. Water each planting hole and allow the water to soak away. Use a dibber or pencil to push the plants out through the base of the plant tray to avoid damaging the plant. Place the rootball in the hole, backfill the soil and gently firm down the area around the plant.

Potting your large-sized plug plants up
We recommend that you pot-on your large plugs as soon as they arrive for best results. Potting them on first allows them time to develop a strong, healthy root system. Our Shuttle Trays with 9cm (4 in) pots are ideal. Use a dibber or pencil to push the plants out through the base of the plant tray to avoid damaging the plant. Handle each plant by the plug root ball, rather than the stem to avoid damage.
Pot each plug into a 9cm (3in) pot using a good multi-purpose compost or a container compost. Water after planting to settle to roots and leave to grow-on in a light, sunny place until the roots have established in the pot before planting outside oncle the plants have established and lots more roots have formed. (following the same instructions as above)

• Mulching round plants with compost or bark chippings will help to keep down weeds and prevent water loss.
• Water regularly during the first year after planting.
• Dead-head when the flowers fade, this will prolong the flowering period of most varieties.
• When the plants die down in the autumn, remove any dead stems or leaves.
• Feed each spring with a general purpose fertiliser and they will return bigger and better each year.