He is currently making bumble bee nests.
The specially designed nests are to encourage bumble bees to pollinate, he told Midweek.
Research has shown that, in many ways, bumble bees are superior pollinators to honey bees, he added.
"Because their larger, furrier bodies collect more pollen from the stamens and make better contact with the pistils than honey bees or other insects."
Part of the drive to make artificial nests is because, unlike honey bee colonies, the bumble bees don't survive from year to year.
Information about the bumble bee shows they are established independently each spring by a new generation of queens reared during the previous summer.
These queens survive the winter by hibernating in the ground until the warmer spring weather arrives. And as soon as they emerge they need to find a good source of nectar.
The queen starts the nest in spring herself and, once the site is chosen, she prepares wax pots to store food and wax cells into which the eggs are laid.
Ivan said the most important thing for the nest searching queen is a safe dry cavity to lay their eggs and brood. So now he has lifestyle block owners, farmers and urban customers from Christchurch through to Northland all ordering his nest boxes.
"These artificial nests are mainly used to pollinate high value glasshouse crops like tomatoes, melons, capsicum and kiwifruit which are all well-pollinated by bumble bees."
Well known New Zealand flower grower Rosemary Read said many growers were wanting to foster bumble bee numbers.
"And providing them with nesting boxes is helping them enormously."
Ivan said he was excited the nesting boxes were becoming very popular.
"I'm very pleased to be making them because it's so worthwhile for our growers - and, of course, the bumble bee colonies."