How to grow & care for Petunia
Petunias are sun loving, summer flowering beauties that provide masses of colour over the warmer months. Petunias love the warm and hot weather of summer, but are frost and cold sensitive - so grow them as an annual plant that you replant each spring or summer.
Petunias are readily available at your local nursery or garden centre as seedlings or larger potted plants. Petunias can also be grown from seeds sown into punnets or small pots and transplanted into your garden once they are big enough.
Plant petunias in pots or hanging baskets where they’ll fill it out quickly and spill over the sides dramatically in cascades of colour! If you’re growing petunias in your garden, planting them in clusters of 3, 5, 7 or more plants will give maximum impact.
Top 5 steps to growing petunias
- Choose a full sun spot in a compost enriched soil or grow in pots or hanging baskets.
- Petunias should be planted after your last frost or in spring/summer when the days are warm.
- Pinch off spent flower heads to encourage more blooms to follow
- Fertilise with Scotts Osmocote All Purpose Controlled Release Fertiliser at planting and fortnightly with Scotts Osmocote Pour+Feed for Flowering Plants for even more flowers.
- Petunias look beautiful spilling over the sides of pots or containers. Use them as the “spiller” plant in potted garden displays.
Shopping List
- Petunia seedlings, potted plants or seeds
- Scotts Osmocote All Purpose Controlled Release Fertiliser
- Scotts Osmocote Pour+Feed for Flowering Plants
- Scotts Osmocote Compost Premium Soil Improver
- Garden trowel
- Mulch
- Defender Pyrethrum Insect Spray
- Defender Snail & Slug Pellets
- If growing in pots, you’ll need Scotts Osmocote Premium Potting Mix + Scotts Osmocote Pour+Feed for Flowering Plants and a suitable pot or container
Preparation & Planting in the garden
Petunias prefer a full sun spot in a free draining soil, but they’ll perform best with regular water during hot weather.
Prepare the site for planting by mixing a little Scotts Osmocote Compost Premium Soil Improver through the original soil - using a garden shovel to turn it through the top 10cm.
Gently remove the petunia seedling or plant from the nursery punnet or pot and tease the roots lightly if they are compact.
Plant your petunias into the prepared soil and backfill around each. Always follow the labels directions for spacing petunia plants or seedlings as some spread out more than others.
Water in well and mulch to suppress weeds and retain moisture.
Growing from seed
Petunias have tiny seeds which are best sown in punnets or small pots filled with Scotts Osmocote Premium Potting Mix. Lightly press the petunia seeds into the potting mix surface and mist them to keep them moist while they germinate in 10-14 days.
Once the seedlings have 2 sets of true leaves they can be transplanted in your garden or large pots.
Planting in pots
Petunias can be grown in any size pot with good drainage. If you’re limited on space, use petunias under taller potted plants - they look beautiful cascading over the side of a pot or grow them in hanging baskets.
Fill your pot or planter with Scotts Osmocote Premium Potting Mix. Gently remove the petunia from the nursery pot and tease the roots lightly if they are compact or separate the plants if they are growing in punnets. Plant the petunias into the potting mix and backfill around each plant. Water in well and top the soil with mulch to retain moisture.
Plant petunias slightly closer in pots than in the ground for a really full display of colour.
Fertilising & Care
Petunias will benefit from a single application of Scotts Osmocote All Purpose Controlled Release Fertiliser at planting plus some extra food for maximum flowering, so apply Scotts Osmocote Pour+Feed for Flowering Plants fortnightly during the growing season.
Deadhead petunias throughout the flowering season to encourage bushy plants and more flowers.
Pests & Diseases
Slugs and Snails can cause significant damage to young petunia seedlings. Protect young plants by setting beer traps (saucers filled with beer) amongst seedlings or use Defender Snail & Slug Pellets.
- Caterpillars can from time to time infest petunia plants - they’ll eat the leaves and flowers. Remove and squash caterpillars as you find them or if needed use a spray like Defender Pyrethrum Insect Spray to control them.
