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Recommended equipment
Strenghten Wrap Up Warm Pest Control  

Cold frame to provide plants with a stable growing environment and to gently get used to life outside.  View our wooden cold frame video clip here

Fleece jackets can be put over plants in containers to provide instant protection from frost.

Slug deterrents such as copper tape or biological pest control.

Strulch garden mulch


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Why Do it?
Hardening off is a gardening term referring to the need to allow plants time to get used to different temperatures and to being outside.

If plants have grown in a greenhouse or on a warm windowsill they are used to quite warm temperatures on a regular basis. They have not learned how to cope with wind or rain. The plants have been living in a sheltered setting. If they are planted straight into the garden they will struggle to survive. Their growth will certainly be slowed down.

Plants described as perennials on the seed packets can be hardened off at any time.

Half-hardy plants such as nasturtiums can be hardened off from the end of April. These plants can cope with a very light air frost provided they are hardened off.

Annual plants such as courgettes and tomatoes should be hardened off at the end of May, beginning of June. These plants cannot cope with even the smallest amount of frost.
Hints and Tips
• Put the trays or pots outside on warm days.

• Bring them inside again at night time.

• Do this for several days.

• Then leave them outside at night and see how they cope.

• Do not leave outside if frost is forecast.

• Put the plants into their permanent planting spot in the vegetable garden.

While plants are inside, you can help them harden off by gently brushing over the top of the plants with the edge of a piece of card. Do this for one minute every day. Each day brush in a different direction. This helps strengthen the plant. But they will still need to get used to different temperatures.
Using a Cold Frame
• Fasten the lid open just a little at first.

• As each day passes, open the lid further.

• Finally, leave the lid open at night.

• Keep the lid closed if frost is forecast.

• Plant outside in their permanent planting position. Water well.

Using Fleece Jackets
• Large pots can be left outside but covered with a fleece jacket overnight.

• Take the jacket off during the day. This will provide ventilation for the plants and allow hardening off to take place.

• When the plant or plants are strong enough remove the fleece jacket at night.

• Don't forget to put the jacket on if there is any possibility of an air frost.
Mulching and Slug Deterrents
Put a mulch around the young plants to maintain moisture in the soil.

A slug deterrent should be placed around vulnerable plants such as strawberries or lettuce. This will prevent slugs from eating the young plants.

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