Bees and finches love lavender. Daisies, whether in wild or cultivated form, are essential because their centres contain an abundance of nectar. Buddleja flowers attract butterflies, insects and birds to the garden.
It is better to fill that space with a decorative plant before nature does it with a weed. A bench or seat close to a tree always provides an excellent focal point. Just make sure you leave enough room for the trunk to expand.