Definition of harden something off in English:

harden something off

Inure a plant to cold by gradually increasing its exposure to it.
More example sentences
  • Add moisture retaining granules and slow release fertiliser to the compost and gradually harden the plants off before putting them outside completely at the end of the month.
  • Not everyone has the luxury of a greenhouse, but plants can be hardened off by taking them outdoors during the day and bringing them in again in the late evening.
  • Gradually harden them off over three to five days by putting them in a protected shady spot, first for half a day, then a full day, and then gradually into full sun.
See parent entry: harden

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Word of the day demoralize
Pronunciation: dɪˈmɒrəlʌɪz
verb
cause (someone) to lose confidence or hope