When To Plant Seeds
With Spring only just around the corner you might be eager to start planting seeds and getting a head start on the year! With that being said, if you are not experienced in sowing seeds in the area you’re in, it is wise to educate yourself on your local climate before sowing your seeds.
All seeds and plants are different, but for ones that are generally started early, indoors in modules or pots before being transplanted to the outdoors, a good rule of thumb is to sow the seeds about 6 weeks before your last frost date.
Doing this means your young seedlings will be ready to plant out when the major risk of frost has passed and they are much more likely to survive and not be damaged by frost.
Last Frost Date
The last frost date is determined by historical data. If frost has not occurred 90% of the time in the past on a date, this is determined as the last frost date. As you can see, even though this is the last frost date, there is still a 10% chance for frost after this date.
The last frost date varies widely throughout Ireland from mid March to mid May. With the South West of Ireland having the earliest last frost date, and parts of the midlands having the latest date.
If you look at Met Eireann's historical data, you can see that Roches Point weather station in Cork got approx 1 day of ground frost every May over a 30 year period, and that Birr weather station in Offaly got approx 7 days of ground frost every May over a 30 year period.
You can use this data to help you decide when is the best time to plant your seeds. The easiest way to find out this information might be to ask a more experienced grower or farmer from your local area about your last frost date, as they would likely have this knowledge.
Why The Last Frost Date Is Important
It is important because planting your seeds at the right time will give you the best chance of success. If you plant seeds too early indoors, you won’t be able to put them outside due to frost risk, and growing seedlings for a long time indoors can lead to leggy and weak plants due to low sunlight levels, and they won’t do well when they are finally put outside.
If you are forced to put them outside early due to a lack of space, their chance of survival is reduced greatly.