9 - Bedding Plants in Protected Environments

Question 1

Describe the seed sowing of bedding plants in a protected environment.

Answer 1

• Small seed can be broadcast in a seed tray
• Large seed can be space sown in a seed tray or sown in modules
• Seed trays are overfilled with a seed sowing growing media and firmed with a presser board to create a firm, level seed bed
• Seed is broadcast evenly at suitable density and lightly covered with growing media as appropriate.

Question 2

Explain the germination environment of bedding plants in a protected environment.

Answer 2

• Seeds require moisture, oxygen and warmth to germinate
• Well aerated but moistyre retentive seed growing media
• Temperature of 18-21C in a greenhouse or growing room.

Question 3

Explain pricking out of bedding plants.

Answer 3

• Carried out once the cotyledon leaves have expanded and can be handled without damage
• Seedlings are teased apart with a dibber and pricked out into seed trays, modules or small pots
• Use suitable growing media (e.g. John Innes No.1)
• A whole large enough to accomodate the root system of the seeding is made using a dibber to a depth so that the cotyledon leaves sit just above the growing media level.

Question 4

What is the germination temperature of Impatiens walleriana?

Answer 4

16-18C

Question 5

Explain the sowing of Impatiens walleriana seed for summer bedding.

Answer 5

• Sow seed in early spring
• Use a peat-based compost
• Sow in modules
• Do not cover the seed as they require light to germinate
• Keep shaded from direct sunlight
• High humidity is beneficial.

Question 6

When do you pot up Impatiens walleriana seedlings?

Answer 6

• When large enough to handle
• Usually 6 weeks
• Pot up into a 9cm pot filled with potting compost.

Question 7

Explain the general cultivation of Impatiens walleriana.

Answer 7

• Continue to grow in a bright but shaded location
• Maintain high humidity level
• Maintain a temperature of 16-18C
• During growth water moderately but do not allow compost to dry out
• Apply a balanced liquid fertiliser monthly
• Deadhead to remove fading leaves every other day to prevent botrytis.

Question 8

Name pests and diseases that affect Impatiens walleriana.

Answer 8

• Vine weevil
• Red spider mite
• White fly
• Botrytis (indoors)