We planted sweet peas some months ago. The plants are growing well on a trellis in a sunny north facing position. The plants are now at least six months old & have no sign of flower buds. What are we doing wrong. They have been watered well. Bryan Green.
Failure to produce flowers is often a sign of excessive nitrogen in the soil. Sweet pea is especially sensitive to this problem because it is in the legume family and can fix its own nitrogen in the roots. It can also be caused by stress from high temperatures.
https://www.gardeningknowhow.com/ornamental/flowers/sweet-pea/sweet-pea-flowers-falling-off.htm
This article is about beans but it's the same idea:
https://www.gardeningknowhow.com/edible/vegetables/beans/get-bean-plants-to-bloom.htm
will they grow thru the summer or will the heat kill them?
I have been to the Imperial Valley in summer, and I am impressed that you are getting anything to grow there! There are some varieties of sweet pea that are supposed to be quite heat tolerant, including the heirloom variety "Cupani". For other varieties you will just have to experiment, or perhaps try growing them in the fall/winter.
Why do my sweet peas have dead leaves at ground level?
This is common, and not really much to worry about. If you are still concerned, then you can refer to these articles: https://www.gardeningknowhow.com/ornamental/flowers/sweet-pea/
We have periennial sweet peas that seem to be taking over the whole garden bed. Can they be cut back and when should this be done - spring or fall?
Yes, perennial sweet peas can (and should) be cut back to prevent them from spreading too far. You can cut back in either spring or fall.
In the areas where you don't want them growing, dig up or mow the plants, then put mulch over the area to prevent re-growth. Also, collect any seed pods that have fallen to prevent the plants from reseeding themselves and spreading.
For the main area where you want the plant to grow, you can cut back 1/3 of the vines each year. Cut off any part of the vine that is spreading into an area where you don't want them.
Is it possible to sow sweetpea seeds directly in to a large patio container now and leave them to germinate and hopefully see them flower next summer without any lifting or potting on. Appreciate your thoughts?
This is possible, and really the better way to do it. They don't particularly like transplanting, so if they can be planted in their terminal pot, then they will appreciate this. Just make sure to plant them 6 inches to a foot apart.
Here is an article for more information: https://www.gardeningknowhow.com/ornamental/flowers/sweet-pea/care-of-sweet-peas.htm
I have some sweet pea flowers growing in my garden. My son used the leaves in a marinade, are these leaves poisonous?
Do not eat these!!! The leaves are only mildly toxic, luckily. This can cause severe intestinal discomfort. Please avoid this in the future!
Our sweetpea bush which was prolific last year has now began to die; yellow, withered leaves, leave leaves falling off and generally looks as though it will not revive. Other friends are having the same problems - do you have any answers to this ?
Sweet pea shrub requires minimal watering. If the soil is staying too wet, the roots will suffer and leaves turn yellow as a result. Imbalances in nutrients in the soil can also lead to yellowing. Potential problems are low magnesium, high potassium and low iron. A soil test to determine whether you have deficiency or toxicity of specific nutrients is important as just throwing down extra nutrients may worsen the problem. Check the website of your state's extension service to see if any diseases are in your area.