Best Time to Plant Geraniums Outside in the UK
Growing geraniums, or pelargoniums, can bring vibrant bursts of color to any garden in the UK. However, since they are not winter hardy perennials and are sensitive to frost, it's essential to wait until the weather is consistently warm. This guide will help you determine the best time to plant geraniums outside in the UK, ensuring your plants thrive.
Understanding the Species
Firstly, it's important to clarify the names used. Geraniums, more commonly known as pelargoniums, are often mistaken for true geraniums, which are frost-tolerant and actually belong to a different genus. True geraniums can be planted in the UK, but for the purpose of this article, we refer to pelargoniums, also known as zonal geraniums or scented geraniums, which are not winter hardy.
When to Plant Geraniums in the UK
The key to successfully growing geraniums outside in the UK is to wait until the risk of frost has passed. While the answer "when there is no longer a risk of frost" might seem straightforward, it's crucial to be precise.
Gardening in the UK involves navigating a complex variety of climates, from temperate regions in the south to more maritime conditions in the west. The average last frost dates can vary significantly across different regions. For instance, areas near the south coast might see frosts as late as May, whereas gardens in the far north could still experience frost as late as June.
Guide to Frost-Free Planting
The UK’s weather patterns are characterized by inconsistencies, making it essential to monitor local climate conditions. This involves staying informed about the likelihood of frost both currently and in the coming weeks. Here are some steps to help you plant your geraniums safely:
Consult Local Agricultural Advisers: They can provide advice on the last average frost date for your specific area. This information can be crucial for gardeners in particularly variable regions. Check Weather Forecasts: Regularly check local weather forecasts to stay informed about upcoming cold snaps or late frosts. Wait for Reliable Warmth: Look for signs of reliable warm temperatures consistently above freezing. This often means waiting until May or early June, depending on your location. Start Indoors: As a precaution, consider starting geraniums indoors in modular trays in late April. This gives them a head start and protects them from unexpected late frosts. Gradual Acclimatization: Once the risk of frost has passed, gradually move your young plants outside to a sheltered area before planting them in the garden. This process, known as hardening off, acclimates them to outdoor conditions.The Role of Microclimates
The UK's varied landscapes mean that microclimates can play a significant role in frost susceptibility. Sheltered spots such as those protected by walls or hedges, or under the eaves of buildings, may provide some frost protection. Conversely, exposed areas may experience earlier and more aggressive frosts.
Conclusion
The best time to plant geraniums outside in the UK is when the risk of frost has reliably passed in your region. By carefully observing local climate conditions, consulting agricultural experts, and following practical steps, you can ensure your geraniums thrive and bring joy to your garden.