Answer: You are correct that it is very difficult to grow old fashioned annual sweet peas in a climate so different from that of the British Isles where they flourish. You might be able to grow some of the newer varieties bred specifically for heat tolerance in dappled light or morning sun in rich, well amended soil with a pH over 6.0 and ample moisture (moist yet well drained so it is not soggy) -- in a cool spring. Plant them out very early, or better yet, in the fall so that they are up and growing as soon as possible. You might also pregerminate the seeds or soak them in tepid water for an hour or so just before planting to hasten germination. Also be sure to dead head them daily to help them bloom longer. They are very heat sensitive, so consider them as an early season annual only and plan to replace them with a more heat-loving vine as soon as the weather turns. As an alternative, you might consider growing the perennial sweet pea; this tough and vigorous plant produces sweet pea blooms in pinks and white but is sadly not particularly fragrant.
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