The Gardener's Almanac

Overview ;

This can be a very busy month subject to what you intend growing.

 

Providing all fears of 'late frosts' has passed most bedding plants can be planted out this month.

 

As a rule of thumb; plant out the 'hardier' annuals first, then follow these with the less hardy varieties.

 

At any time this month;

• Inspect lilies for signs of Scarlet lily beetles which are usually active at this time of the year.

 

• Ensure that tall plants have adequate support.

 

• Keep up with deadheading e.g. Azaleas, Camellias, Narcissus, Rhododendrons and Tulips.

 

• Plant out containerised shrubs, roses and perennials.

 

• Thin out congested aquatic plants.

 

 

Week No. 18 - 30th Apr to 5th May

 

• If not done previously apply a top dressing of general fertiliser in readiness for planting out.

 

• Plant out Aethiopica italicum, Althaea, Azalea, Celastrus, Choisya, Cistus, Escallonia, Euphorbia, Gladioli, Gunnera, Juniper,

and Roses.

 

• Divide Crepsis, Platycodon, and Thyme, if required.

 

• Sow Arctotsis, and Calendula, seed insitu if soil conditions allow.

 

• Feed established Abies, Echinacea, Geranium and Kniphofia.

 

• If required; plant up planters / containers with Arctotsis, and Pelargoniums.

 

• Mulch around permanently planted alpines, and Abies, Lonicera, and Meconopsis,

 

• Commence feeding Brugmansia, Cranesbill / Geranium, Datura, Echinacea, Kniphofia, Lonicera, and Nerium.

 

• Cut back Buxus, Ceanothus, Cortaderia, Eucalyptus,Hebe, Jasmine nudiflorum, and Penstemon if necessary .

 

• Prepare beds to receive Chrysanthemums, and Dianthus chinensis,

 

• Be on the lookout for Lupin aphid.

 

Week No. 19 - 6th to 12th

 

• Prepare bed for Dahlias.

 

• Plant out Penstemon if conditions allow.

 

• Prune/Tidy up Fatsia japonica,

 

Week No. 20 - 13th to 19th

 

• Plant out Asarina, Briza, Catananche, Chrysanthemums, Clarkia, Cornus, Dierama, Eucomis, Helianthus, Incarvillea, Lilies, Lupin,

Ranunculus, and Viola, if conditions allow.

 

• Divide and replant Agapanthus, Ajuga, Dierama, Eucomis, Gunnera, Pulmonaria, and Saxifrage, if deemed necessary.

 

• Lift, replant or pot up self seeded Lunaria.

 

• Place Canterbury Bells in coldframe to harden off.

 

• Pinch out the growing points of Actinidia arguta and chinensis when quite young,

 

• Feed Aethiopica, with a balanced liquid fertiliser at weekly intervals from now until August.

 

• Do not allow Hamamelis mollis to dry out, water and mulch if necessary.

 

• Spray roses to prevent major outbreaks of pests and diseases.

 

• Deadhead Pieris after flowering.

 

• Cut Narcissus and Tulip down to ground level when the leaves have turned yellow.

 

• Narcissus and Tulip bulbs can be lifted and placed into store for planting elsewhere in autumn.

 

• Commence Chrysanthemum 'stopping' programme.

 

 

Week No. 21 - 20th to 26th

 

• If not done previously prepare beds for planting out.

 

• Plant out Agastache, Agrostemma, Anomatheca, Arthropodium, Calendula, Callistephus, Carnations, Centaurea cyanus,

Chrysanthemum annuals, Dianthus chinensis, Echium, Eschscholtzia, Gaillardia, Godetia, Gypsophila, Helichrysum, Iberis,

Lavatera, Limnanthes, Limonium, Linaria, Lobelia, Lychnis, Mimulus, Nemophila, Nicotiana, Nigella, Nolana, Orache,

Papaver / Poppy, Phlox drummondii, Portulaca, Reseda, Rudbeckia, Salpiglossis, Salvia, Schizanthus, Silene, Tropaeolum /

Nasturtium. and Verbena, if conditions allow

 

• Place potted Camellias outdoors for the summer.

 

• Layer Wisteria if required.

 

• Divide Papaver / Poppy,

 

• Pinch out the tops of Salvia, to encourage branching.

 

• Watch out for signs of leaf spot and rhizome rot on Bearded Iris,

 

Week No. 22 - 27th to 2nd Jun

 

• Plant out Ageratum, Alstroemeria, Alyssum, Amaranthus, Antirrhinums, Arctotsis, Bidens, Brachycome, Celosia, Cerinthe,

Convolvulus, Cosmos, Dahlias, Gazania, Gerbera, Impatiens balsamina, Ipomea, Pacific Coast Iris, Laurentia, Lewisia,

Marigolds, Mesembryanthemum, Nemesia, Nerium, Osteospermum, Pansy, Passiflora, Tagetes, Thunbergia, and Zinnia.

 

• Trim back Aubretia, Choisya, Narcissus / Daffodil, after flowering.

 

• Keep Gladioli bed weed free.

 

• Pot up Dahlias to grow as 'pot tubers'