Selling house plants on eBay as a hobby

My husband has been growing tender house plants as a hobby over the last 3 years in the house. As the plants have started to multiply and now lack of space in the house, he has decided to sell some on eBay this year. He is a pensioner and pay tax on his pension. Is he liable to pay tax on his hobby? Bearing in mind over the last 3 years there is a cost of heating, lighting, compost, pots and the original cost of the plants. Thank you

Hi emitch Mitchell,
If you husband is intending selling the houseplant, then he is commencing as a self employed seller of plants.
If the turnover he receives from selling the plants, exceeds £1000.00 in a tax year, he will need to register as self employed and complete a Self Assessment Tax return. Your husband will be able to set expenses against the payments received and may be subject to tax on the net profit.  
Guidance here: 
Check if you need to send a Self Assessment tax return
Register for Self Assessment
Thank you.