When it comes to maintaining the perfect garden even Monty Don would be proud of, there are a lot of rules to follow.

One person that knows these rules better than most is Mike Gogerty, head gardener at Birtsmorton Court, a Grade I listed fortified medieval moated manor house near Malvern in Worcestershire.

A gardener with a Royal Horticultural Society qualification, Mr Gogerty is gearing up for the National Garden Scheme, where visitors can gain a rare insight into the gardens of Birtsmorton Court.

Ahead of the event, the head gardener has shared his top nine gardening tips to act upon now - including the one sweet pea mistake even the most green fingered gardeners make.

1. Sweet pea tying and harvesting

When it comes to sweet pea tying and harvesting, Mr Gogerty recommends harvesting them often.

"With sweet peas they need to be harvested on the regular," he said."

"So if you don't harvest them they go to seed and take a lot of energy out of the plant and the plant feels like it has done its job. "

"We harvest the tired looking flowers when we can so they can produce more."

He then suggests tying in the growth with raffia string to encourage straighter growth.

"It's good for the plant and biodegrades," he added. "

2. Feeding tomatoes

With feeding tomatoes, Mr Gogerty suggests using a feed spray gun attached to a hose rather than mixing feed into a watering can to save time.

"The hose mixes it for you with the water to help your tomatoes grow," Mr Gogerty said. "

3. Weeding

"It's best to weed on your hands and knees with a small all purpose hooked weeding knife," the gardening expert recommends. "

You can use your hands for this rather than a hoe as it's easier to make sure you have got all the roots out.

4. Lettuce harvesting

Rather than harvesting the whole lettuce at once in the greenhouse, Mr Gogery suggests picking off the outside leaves which will then keep growing out from the inside. This means it will be a continuous crop.

"The lettuce can be started early in the greenhouse due to the warmth around April," he added. "

5. Pricking out lettuce seedlings

Mr Gogerty advises to reuse plastic trays each year for lettuce seedlings. Reuse, fill with compost, remove any lumps, flatten down, poke holes and then water the compost he instructs.

"You can get special pricking out tools but you can use just a piece of dowel or a wooden plant label/lolly stick which works just as well."

6. Dead heading roses

When it comes to dead heading roses, the head gardener suggests thinking of it more like summer pruning.

He said: "So if on a stem of three roses, two have gone and you know the final rose"
won't have long, you should prune it right back at the end of the stem as it will then regrow in a few weeks time.

"Don't be afraid to cut back as it's not just dead heading, you have to be ruthless," he added"

7. Wildflower meadow establishing

If you are trying to grow a wildflower meadow, Mr Gogerty advises planting Yellow Rattle.

This is because grass grows too high in fertile soil and so this reduces grass growth and allows the wildflowers such as Leucanthemum Vulgare - Oxeye Daisies to establish.

8. Feeding pelargonium

With feeding pelargonium, you should do a granular feed every week.

Mr Gogerty advises to use two scoops of all purpose plant food into a large watering can then decant into a smaller watering can to concentrate on each individual plant.

This allows each one to get the right amount of food.

"Also put in continuous release plant food, to help add feed throughout the season," he added as this sits on top of the compost and releases feed through the compost when it needs it."

9. Cutting a box hedge

When cutting a box hedge, use an electric hedge trimmer first then go back over it with hand shears afterwards. This allows you to get a tighter cut, the head gardener advises.

"ARS KR-1000 is the perfect tool for this as they're ultra light, sharp and good for awkward angles. The best time to do it is anytime from the end of May to the beginning of June," he said."