If the soil is too dry, it will soak up all the water from your bottle before you even leave for your trip. Having the soil already damp before you begin will ensure that the plant doesn't soak up the water too fast. If you have a smaller plant to take care of, a smaller bottle will do just fine. Since you will be burying this bottle in the soil, this method will work best for garden plants or plants in large containers. This is very important. If you don't have any drain holes at the bottom of the bottle, the water will sit instead of draining out. This can lead to algae growth. You don't need a lot; 3 to 5 holes will be plenty. If you put in too many holes, the water will leak out too fast, which you don't want.  Place the holes on 1 side of the bottle. When you put the bottle into the soil, turn it so that the holes face the plant you are watering. It's better to start with too few holes than too many. You can always add more holes later if there aren't enough, but it will be difficult to cover up holes that are already there. The hole needs to be deep enough to cover the bottle up to the neck. At this point, you can also add some liquid fertilizer as well. Gently pat the soil around the bottle and be careful not to get any inside it. The lid will help slow down the rate of water flow; this is great for plants that don't need a lot of water, or if you will be gone for a long time. The tighter you screw on the lid, the slower the water will flow out. Make a mark on the bottle with a marker, right at the water level. Check back after a few hours. If the water level has not changed, loosen the cap a little. If the water level has dropped significantly, tighten the cap.

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Write a summary of the previous text in Vietnamese:
Đảm bảo đất phải hoàn toàn ẩm. Tìm một chai nhựa 2 lít. Dùng búa và đinh đục 2 lỗ dưới đáy chai. Đục 3-5 lỗ trên thành chai. Đào một hố đất cạnh cây muốn tưới. Rót nước vào chai, sau đó đặt chai xuống hố. Đậy nắp chai nếu bạn muốn.