This post should also be entitled: how to keep your garden warm, cheaply, in unpredictable spring weather.
The problem with spring is its unpredictability. Yesterday, the high was in the low 60s, but the low was in the low 40s. Heat-loving vegetables may not like the lows at night. Additionally, it alternated between DUMPING rain and being nice and sunny. You never really know what you're going to get. Two years ago, there was a heat wave that gave us 106 degree weather for two days.
It's not just like this in Oregon, it's like this in many other places. So, I thought I'd post about what methods I'm using to keep my plants happy, regardless of weather.
First up: Hot caps.
Now, many magazines advertise for hot caps. They usually run about $3 apiece, and they are called "wall of water" or just plain hot caps. The nice thing about hot caps is that you can generally still water around them and the water will seep to the plant's roots. And, if you want to, the hot caps are pretty easily removable. That is one key thing to remember when looking to protect your plants: How easily can you change it to match the weather. You don't want your plant to roast in 100+ weather because the protection is still present.
I find the $3(+) pricetag on the hot caps a bit unsettling. So, I've had my coworkers save their gallon milk jugs. Cut out the bottom, place it over the plant, and remove the cap (for heat release. Alternatively, you can cut out the top and poke holes in the bottom.
I did this yesterday with my sweet potatoes. I didn't have enough for all of them, but I had about 12. That's 12 free hotcaps.
Yes, it doesn't look amazingly stunning, but right now, I am pretty much (well, plus B and my neighbor) the only person that sees my garden. I can deal with the milk jug hot caps.
As you can see, it works. See the condensation inside the hot cap?
The hot caps also protect against rain. A little may get in through the top, but the plant won't be trampled in a torential downpour.
Martha Stewart (may she live forever-- but I'm critiquing her here...) has recommended these hot caps. The problem I have with these, is that they will smash when it rains. Plastic is a gardener's assistant and problematic beast. It keeps plants warm, but if water is put on top of plastic, the lack absorbency of the plastic can smush the plant as the plastic is pressed down.
If you want to try the Martha type of hot cap, I recommend you first try using large coffee filters. It's pretty much the same thing. You can stick a shish kabob stick in the middle of the filter, that way, if it gets wet, it's not bringing down your plant. This is a much cheaper method than buying hot caps for 50 cents each. AND, they're compostable and easily replaceable.
The next method is plastic. You need to go for a clear/opaque plastic, so that sun can get through. However, if you live somewhere where you get spring rainstorms, you need to think about drainage. Otherwise, the rain will puddle up on top of the plastic, and come crashing down on your seedlings, smushing them.
Right now, I have plastic on my basil and lettuce/arugula beds. The lettuce does not need plastic, but I want it to germinate quickly, so I'm giving it a little extra boost. However, I don't have a great system in place right now for drainage, so I have to go outside pretty frequently to dump water off the plastic. Yes, fixing it to be a better system is on my to-do list. Still, you can see that there is condensation and warmth inside the bed under the plastic.
The final method I'm using right now is my cold frame. I have my tomatoes (still...) in here right now. The general rule of thumb here is that you can plant your tomatoes after Mother's day. I just didn't feel ready. I'm glad I waited too. I would have been scrambling for hot caps and plastic. The cold frame saves me from that.
Right now, my peppers, tomatillos, tomatoes, and ground cherries are in the cold frame. My goal is to get their beds set up asap and have them in the beds soon, but the weather is not pushing me to do this. I suspect after June 1, I'll be much safer to transplant.
On days like today (60 degrees but a 90% chance of rain and wind), the cold frame stays closed. Sun still comes in through the window, but the plants are protected from the rain and wind. And, I can tell it's working based upon the condensation on the glass. If the cold frame was opened up, that condensation would go. Condensation= protection and warmth inside.
But other plants in my garden don't have the protection of the ones mentioned above. My potatoes are not covered, and neither are any of my fruits or my peas or broccoli.
My onions seem to be doing well. Actually, this lack of super-sunny weather has been good for me; the onions are continuing to grow rather than bulb. I needed them to grow. I will still probably make a sun shade this week (I want the onions to continue to grow before they really start bulbing), but the weather has been on my side as far as the onions go.
The red onions I started from sets indoors really took off. I think next year, I'll start these in January, but have them indoors at first, and then outdoors in plastic. They loved the plastic in March this year.
And, the blueberries love the weather too. This is just one plant, and you can see all the green clusters. I can't wait to pick, though I suspect we will be out there picking for hours.
Close-up view of the green little things.
I should add that spring weather is also a great time to treat your plants at their bases. Why? Because rain will slowly soak it in for you. Does your ground need more nitrogen? You can add a slow-releasing nitrogen like coffee grounds (check what plants you want to use this on first). I need to add pine shavings to my blueberries too. I side-treated my garlic and my roses with blood meal. Roses love the stuff, and it encourages bulb growth in garlic. I've heard it also works on onions, so I'm going to throw some on my onions in the next few days.