Grow Well Guides


Pretty petunias are one of summer’s most stunning flowering plants, petunias are a hardy and heat tolerant blooming annual. These characteristics make them perfect for almost any spot in the garden, as well as outdoor pots and hanging baskets. Great for filling up empty spaces in your garden beds, petunias also make a gorgeous statement when cascading down living walls or used as a feature in planters.

Planting Calendar


If growing from seed, the annual or bedding petunias can be started in late spring when the weather warms up. Sow the seeds indoors in seed trays and do not plant the seedlings outside till the last frosts have gone. If planting seedlings available in garden centres, plant the petunias in Autumn through to Spring.



Petunias need a hot sunny position with protection from strong winds.


When planted into the ground Petunias like a free draining soil that is rich in organic matter. To improve the organic content in your soil, break up the soil and add Kings Compost and Kings Sheep Pellets then mix together well. When growing in containers, plant into Kings Container mix. This mix contains added water storage crystals and Saturaid, two products that help maintain moisture in the soil.


Mix Kings Compost into your existing soil at a 50/50 ratio, add Sheep Pellets and Novatec Premium Fertiliser, then mix together well. Dig a hole large enough to accommodate the seedling roots. Back fill the hole with this soil, so that when planted the top of the plant’s roots sit level with the surrounding ground. Firm the soil down gently and water in well with Aquaticus Organic Garden Booster. In heavier clay soils, where drainage is likely to be an issue, plant onto a raised mound and sprinkle Gypsum Clay Breaker into the bottom of the hole, this helps slowly condition the soil and will help to break down the clay. When planting into containers, plant in Kings Containers mix, as this has water retention crystals in it, which will help in keeping the soil moist. Firm the soil down gently and water in well with Aquaticus Organic Garden Booster.



Petunias planted in the garden and pots will need a thorough watering two to three a week, however plants in hanging baskets will require daily watering. Water slowly allowing the water to sink down into the roots, rather than allowing it to run off the top of the soils surface. Add Saturaid into the soil at planting as this will help channel the water deep down into the root zone. If planted in pots never allow the pot to sit in water.


When planted in the ground liquid feed every month with Aquaticus Garden Booster, from Spring through to the end of Autumn, this encourages root growth and increases the microbial activity in the soil. Monthly applications of Kings Sheep Pellets will help with soil conditioning and plant health. If planted into a container, feed with Kings Liquid Fast Food along with monthly applications of Aquaticus Organic Garden Booster this encourages strong roots and a healthy immune system.


Protect your seedling from slugs and snails by applying Tui Quash, Re-apply after rain. Avoid getting the leaves wet when watering, as this can encourage powdery mildew.


If mildew is noticed spray with Yates Supershield this will also keep any insects under control. Early intervention is important.


The only pruning required is to remove old flowers (deadhead) this will encourage repeat flowering.

General Care

When using sprays, chemicals or fertilisers always read the label and follow the instructions. Apply sprays in the evening to avoid harming beneficial insects.

Expert Tip

While Petunia can cope with some dryness, this can affect flowering so it is best to keep the soil moist.

Top Varieties



Traditionally called bubblegum petunias, supertunias have vigorous growth and mounding flower habits, making them perfect for the garden or large hanging baskets. Available in a range of whites, pinks and reds, double-planted supertunias will result in huge clouds of colour and create a stunning display.

All you need to grow well.

Frequently Asked Questions