(Image credit: Shutterstock) I’m an impatient gardener, and I often get frustrated waiting for seeds to come into flower, but this month I’ll be sowing some quick-starters to enjoy almost instant color. Apart from satisfying my eagerness to see a garden full of bright hues, these quick bloomers will help fill in my beds, borders and containers while I wait for other plants to come to life. Rather than spending money on already-established nursery plants, these quick bloomers are perfect to grow from seed, and are one sure way to save money in the garden. What’s more, right now in May, with the soil starting to warm, it's the ideal time to direct sow outdoors, making these flowers both budget-friendly and easy to grow. Here I share my favorite five flowers I’ll be sowing in my own backyard this month. 1. Cosmos (Image credit: Shutterstock) Cosmos are beautiful, delicate flowers. But apart from their golden centers and delicate petals, I love their airy foliage.…